html_interaction.c

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/*
 * Copyright 2006 James Bursa <bursa@users.sourceforge.net>
 * Copyright 2006 Richard Wilson <info@tinct.net>
 * Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
 * Copyright 2009 Paul Blokus <paul_pl@users.sourceforge.net>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * \file
 * implementation of user interaction with a CONTENT_HTML.
 */

#include <assert.h>
#include <stdbool.h>

#include <dom/dom.h>

#include "utils/corestrings.h"
#include "utils/messages.h"
#include "utils/utils.h"
#include "utils/log.h"
#include "utils/nsoption.h"
#include "netsurf/content.h"
#include "netsurf/browser_window.h"
#include "netsurf/mouse.h"
#include "netsurf/misc.h"
#include "netsurf/layout.h"
#include "netsurf/keypress.h"
#include "content/hlcache.h"
#include "desktop/frames.h"
#include "desktop/scrollbar.h"
#include "desktop/selection.h"
#include "desktop/textarea.h"
#include "javascript/js.h"
#include "desktop/gui_internal.h"

#include "html/box.h"
#include "html/box_textarea.h"
#include "html/font.h"
#include "html/form_internal.h"
#include "html/html_internal.h"
#include "html/imagemap.h"
#include "html/search.h"

/**
 * Get pointer shape for given box
 *
 * \param box       box in question
 * \param imagemap  whether an imagemap applies to the box
 */

static browser_pointer_shape get_pointer_shape(struct box *box, bool imagemap)
{
        browser_pointer_shape pointer;
        css_computed_style *style;
        enum css_cursor_e cursor;
        lwc_string **cursor_uris;

        if (box->type == BOX_FLOAT_LEFT || box->type == BOX_FLOAT_RIGHT)
                style = box->children->style;
        else
                style = box->style;

        if (style == NULL)
                return BROWSER_POINTER_DEFAULT;

        cursor = css_computed_cursor(style, &cursor_uris);

        switch (cursor) {
        case CSS_CURSOR_AUTO:
                if (box->href || (box->gadget &&
                                (box->gadget->type == GADGET_IMAGE ||
                                box->gadget->type == GADGET_SUBMIT)) ||
                                imagemap) {
                        /* link */
                        pointer = BROWSER_POINTER_POINT;
                } else if (box->gadget &&
                                (box->gadget->type == GADGET_TEXTBOX ||
                                box->gadget->type == GADGET_PASSWORD ||
                                box->gadget->type == GADGET_TEXTAREA)) {
                        /* text input */
                        pointer = BROWSER_POINTER_CARET;
                } else {
                        /* html content doesn't mind */
                        pointer = BROWSER_POINTER_AUTO;
                }
                break;
        case CSS_CURSOR_CROSSHAIR:
                pointer = BROWSER_POINTER_CROSS;
                break;
        case CSS_CURSOR_POINTER:
                pointer = BROWSER_POINTER_POINT;
                break;
        case CSS_CURSOR_MOVE:
                pointer = BROWSER_POINTER_MOVE;
                break;
        case CSS_CURSOR_E_RESIZE:
                pointer = BROWSER_POINTER_RIGHT;
                break;
        case CSS_CURSOR_W_RESIZE:
                pointer = BROWSER_POINTER_LEFT;
                break;
        case CSS_CURSOR_N_RESIZE:
                pointer = BROWSER_POINTER_UP;
                break;
        case CSS_CURSOR_S_RESIZE:
                pointer = BROWSER_POINTER_DOWN;
                break;
        case CSS_CURSOR_NE_RESIZE:
                pointer = BROWSER_POINTER_RU;
                break;
        case CSS_CURSOR_SW_RESIZE:
                pointer = BROWSER_POINTER_LD;
                break;
        case CSS_CURSOR_SE_RESIZE:
                pointer = BROWSER_POINTER_RD;
                break;
        case CSS_CURSOR_NW_RESIZE:
                pointer = BROWSER_POINTER_LU;
                break;
        case CSS_CURSOR_TEXT:
                pointer = BROWSER_POINTER_CARET;
                break;
        case CSS_CURSOR_WAIT:
                pointer = BROWSER_POINTER_WAIT;
                break;
        case CSS_CURSOR_PROGRESS:
                pointer = BROWSER_POINTER_PROGRESS;
                break;
        case CSS_CURSOR_HELP:
                pointer = BROWSER_POINTER_HELP;
                break;
        default:
                pointer = BROWSER_POINTER_DEFAULT;
                break;
        }

        return pointer;
}


/**
 * Start drag scrolling the contents of a box
 *
 * \param box   the box to be scrolled
 * \param x     x ordinate of initial mouse position
 * \param y     y ordinate
 */

static void html_box_drag_start(struct box *box, int x, int y)
{
        int box_x, box_y;
        int scroll_mouse_x, scroll_mouse_y;

        box_coords(box, &box_x, &box_y);

        if (box->scroll_x != NULL) {
                scroll_mouse_x = x - box_x ;
                scroll_mouse_y = y - (box_y + box->padding[TOP] +
                                box->height + box->padding[BOTTOM] -
                                SCROLLBAR_WIDTH);
                scrollbar_start_content_drag(box->scroll_x,
                                scroll_mouse_x, scroll_mouse_y);
        } else if (box->scroll_y != NULL) {
                scroll_mouse_x = x - (box_x + box->padding[LEFT] +
                                box->width + box->padding[RIGHT] -
                                SCROLLBAR_WIDTH);
                scroll_mouse_y = y - box_y;

                scrollbar_start_content_drag(box->scroll_y,
                                scroll_mouse_x, scroll_mouse_y);
        }
}


/**
 * End overflow scroll scrollbar drags
 *
 * \param html   html content
 * \param mouse  state of mouse buttons and modifier keys
 * \param x      coordinate of mouse
 * \param y      coordinate of mouse
 * \param dir    Direction of drag
 */
static size_t html_selection_drag_end(struct html_content *html,
                browser_mouse_state mouse, int x, int y, int dir)
{
        int pixel_offset;
        struct box *box;
        int dx, dy;
        size_t idx = 0;

        box = box_pick_text_box(html, x, y, dir, &dx, &dy);
        if (box) {
                plot_font_style_t fstyle;

                font_plot_style_from_css(&html->len_ctx, box->style, &fstyle);

                guit->layout->position(&fstyle, box->text, box->length,
                                       dx, &idx, &pixel_offset);

                idx += box->byte_offset;
        }

        return idx;
}


/**
 * Handle mouse tracking (including drags) in an HTML content window.
 *
 * \param  c      content of type html
 * \param  bw     browser window
 * \param  mouse  state of mouse buttons and modifier keys
 * \param  x      coordinate of mouse
 * \param  y      coordinate of mouse
 */

void html_mouse_track(struct content *c, struct browser_window *bw,
                browser_mouse_state mouse, int x, int y)
{
        html_mouse_action(c, bw, mouse, x, y);
}

/**
 * Helper for file gadgets to store their filename.
 *
 * Stores the filename unencoded on the dom node associated with the
 * gadget.
 *
 * \todo Get rid of this crap eventually
 *
 * \param operation DOM operation
 * \param key DOM node key being considerd
 * \param _data The data assocated with the key
 * \param src The source DOM node.
 * \param dst The destination DOM node.
 */
static void
html__image_coords_dom_user_data_handler(dom_node_operation operation,
                                         dom_string *key,
                                         void *_data,
                                         struct dom_node *src,
                                         struct dom_node *dst)
{
        struct image_input_coords *oldcoords, *coords = _data, *newcoords;

        if (!dom_string_isequal(corestring_dom___ns_key_image_coords_node_data,
                                key) || coords == NULL) {
                return;
        }

        switch (operation) {
        case DOM_NODE_CLONED:
                newcoords = calloc(1, sizeof(*newcoords));
                if (newcoords != NULL) {
                        *newcoords = *coords;
                        if (dom_node_set_user_data(dst,
                                 corestring_dom___ns_key_image_coords_node_data,
                                 newcoords,
                                 html__image_coords_dom_user_data_handler,
                                 &oldcoords) == DOM_NO_ERR) {
                                free(oldcoords);
                        }
                }
                break;

        case DOM_NODE_DELETED:
                free(coords);
                break;

        case DOM_NODE_RENAMED:
        case DOM_NODE_IMPORTED:
        case DOM_NODE_ADOPTED:
                break;

        default:
                NSLOG(netsurf, INFO, "User data operation not handled.");
                assert(0);
        }
}


/**
 * End overflow scroll scrollbar drags
 *
 * \param  scrollbar  scrollbar widget
 * \param  mouse   state of mouse buttons and modifier keys
 * \param  x       coordinate of mouse
 * \param  y       coordinate of mouse
 */
static void
html_overflow_scroll_drag_end(struct scrollbar *scrollbar,
                              browser_mouse_state mouse,
                              int x, int y)
{
        int scroll_mouse_x, scroll_mouse_y, box_x, box_y;
        struct html_scrollbar_data *data = scrollbar_get_data(scrollbar);
        struct box *box;

        box = data->box;
        box_coords(box, &box_x, &box_y);

        if (scrollbar_is_horizontal(scrollbar)) {
                scroll_mouse_x = x - box_x;
                scroll_mouse_y = y - (box_y + box->padding[TOP] +
                                box->height + box->padding[BOTTOM] -
                                SCROLLBAR_WIDTH);
                scrollbar_mouse_drag_end(scrollbar, mouse,
                                scroll_mouse_x, scroll_mouse_y);
        } else {
                scroll_mouse_x = x - (box_x + box->padding[LEFT] +
                                box->width + box->padding[RIGHT] -
                                SCROLLBAR_WIDTH);
                scroll_mouse_y = y - box_y;
                scrollbar_mouse_drag_end(scrollbar, mouse,
                                scroll_mouse_x, scroll_mouse_y);
        }
}


/**
 * Handle mouse clicks and movements in an HTML content window.
 *
 * \param  c      content of type html
 * \param  bw     browser window
 * \param  mouse  state of mouse buttons and modifier keys
 * \param  x      coordinate of mouse
 * \param  y      coordinate of mouse
 *
 * This function handles both hovering and clicking. It is important that the
 * code path is identical (except that hovering doesn't carry out the action),
 * so that the status bar reflects exactly what will happen. Having separate
 * code paths opens the possibility that an attacker will make the status bar
 * show some harmless action where clicking will be harmful.
 */

void html_mouse_action(struct content *c, struct browser_window *bw,
                browser_mouse_state mouse, int x, int y)
{
        html_content *html = (html_content *) c;
        enum { ACTION_NONE, ACTION_SUBMIT, ACTION_GO } action = ACTION_NONE;
        const char *title = 0;
        nsurl *url = 0;
        char *url_s = NULL;
        size_t url_l = 0;
        const char *target = 0;
        char status_buffer[200];
        const char *status = 0;
        browser_pointer_shape pointer = BROWSER_POINTER_DEFAULT;
        bool imagemap = false;
        int box_x = 0, box_y = 0;
        int gadget_box_x = 0, gadget_box_y = 0;
        int html_object_pos_x = 0, html_object_pos_y = 0;
        int text_box_x = 0;
        struct box *url_box = 0;
        struct box *gadget_box = 0;
        struct box *text_box = 0;
        struct box *box;
        struct form_control *gadget = 0;
        hlcache_handle *object = NULL;
        struct box *html_object_box = NULL;
        struct browser_window *iframe = NULL;
        struct box *drag_candidate = NULL;
        struct scrollbar *scrollbar = NULL;
        plot_font_style_t fstyle;
        int scroll_mouse_x = 0, scroll_mouse_y = 0;
        int padding_left, padding_right, padding_top, padding_bottom;
        browser_drag_type drag_type = browser_window_get_drag_type(bw);
        union content_msg_data msg_data;
        struct dom_node *node = html->layout->node; /* Default to the <HTML> */
        union html_drag_owner drag_owner;
        union html_selection_owner sel_owner;
        bool click = mouse & (BROWSER_MOUSE_PRESS_1 | BROWSER_MOUSE_PRESS_2 |
                        BROWSER_MOUSE_CLICK_1 | BROWSER_MOUSE_CLICK_2 |
                        BROWSER_MOUSE_DRAG_1 | BROWSER_MOUSE_DRAG_2);

        nserror res = NSERROR_OK;

        if (drag_type != DRAGGING_NONE && !mouse &&
                        html->visible_select_menu != NULL) {
                /* drag end: select menu */
                form_select_mouse_drag_end(html->visible_select_menu,
                                mouse, x, y);
        }

        if (html->visible_select_menu != NULL) {
                box = html->visible_select_menu->box;
                box_coords(box, &box_x, &box_y);

                box_x -= box->border[LEFT].width;
                box_y += box->height + box->border[BOTTOM].width +
                                box->padding[BOTTOM] + box->padding[TOP];
                status = form_select_mouse_action(html->visible_select_menu,
                                mouse, x - box_x, y - box_y);
                if (status != NULL) {
                        msg_data.explicit_status_text = status;
                        content_broadcast(c, CONTENT_MSG_STATUS, &msg_data);
                } else {
                        int width, height;
                        struct hlcache_handle *bw_content;
                        form_select_get_dimensions(html->visible_select_menu,
                                        &width, &height);
                        html->visible_select_menu = NULL;
                        bw_content = browser_window_get_content(bw);
                        content_request_redraw(bw_content,box_x, box_y,
                                               width, height);
                }
                return;
        }

        if (html->drag_type == HTML_DRAG_SELECTION) {
                /* Selection drag */
                struct box *box;
                int dir = -1;
                int dx, dy;

                if (!mouse) {
                        /* End of selection drag */
                        int dir = -1;
                        size_t idx;

                        if (selection_dragging_start(&html->sel))
                                dir = 1;

                        idx = html_selection_drag_end(html, mouse, x, y, dir);

                        if (idx != 0)
                                selection_track(&html->sel, mouse, idx);

                        drag_owner.no_owner = true;
                        html_set_drag_type(html, HTML_DRAG_NONE,
                                        drag_owner, NULL);
                        return;
                }

                if (selection_dragging_start(&html->sel))
                        dir = 1;

                box = box_pick_text_box(html, x, y, dir, &dx, &dy);

                if (box != NULL) {
                        int pixel_offset;
                        size_t idx;
                        plot_font_style_t fstyle;

                        font_plot_style_from_css(&html->len_ctx,
                                        box->style, &fstyle);

                        guit->layout->position(&fstyle,
                                               box->text, box->length,
                                               dx, &idx, &pixel_offset);

                        selection_track(&html->sel, mouse,
                                        box->byte_offset + idx);
                }
                return;
        }

        if (html->drag_type == HTML_DRAG_SCROLLBAR) {
                struct scrollbar *scr = html->drag_owner.scrollbar;
                struct html_scrollbar_data *data = scrollbar_get_data(scr);

                if (!mouse) {
                        /* drag end: scrollbar */
                        html_overflow_scroll_drag_end(scr, mouse, x, y);
                }

                box = data->box;
                box_coords(box, &box_x, &box_y);
                if (scrollbar_is_horizontal(scr)) {
                        scroll_mouse_x = x - box_x ;
                        scroll_mouse_y = y - (box_y + box->padding[TOP] +
                                        box->height + box->padding[BOTTOM] -
                                        SCROLLBAR_WIDTH);
                        status = scrollbar_mouse_status_to_message(
                                        scrollbar_mouse_action(scr, mouse,
                                                        scroll_mouse_x,
                                                        scroll_mouse_y));
                } else {
                        scroll_mouse_x = x - (box_x + box->padding[LEFT] +
                                        box->width + box->padding[RIGHT] -
                                        SCROLLBAR_WIDTH);
                        scroll_mouse_y = y - box_y;
                        status = scrollbar_mouse_status_to_message(
                                        scrollbar_mouse_action(scr, mouse,
                                                        scroll_mouse_x,
                                                        scroll_mouse_y));
                }

                msg_data.explicit_status_text = status;
                content_broadcast(c, CONTENT_MSG_STATUS, &msg_data);
                return;
        }

        if (html->drag_type == HTML_DRAG_TEXTAREA_SELECTION ||
                        html->drag_type == HTML_DRAG_TEXTAREA_SCROLLBAR) {
                box = html->drag_owner.textarea;
                assert(box->gadget != NULL);
                assert(box->gadget->type == GADGET_TEXTAREA ||
                                box->gadget->type == GADGET_PASSWORD ||
                                box->gadget->type == GADGET_TEXTBOX);

                box_coords(box, &box_x, &box_y);
                textarea_mouse_action(box->gadget->data.text.ta, mouse,
                                x - box_x, y - box_y);

                /* TODO: Set appropriate statusbar message */
                return;
        }

        if (html->drag_type == HTML_DRAG_CONTENT_SELECTION ||
                        html->drag_type == HTML_DRAG_CONTENT_SCROLL) {
                box = html->drag_owner.content;
                assert(box->object != NULL);

                box_coords(box, &box_x, &box_y);
                content_mouse_track(box->object, bw, mouse,
                                x - box_x, y - box_y);
                return;
        }

        if (html->drag_type == HTML_DRAG_CONTENT_SELECTION) {
                box = html->drag_owner.content;
                assert(box->object != NULL);

                box_coords(box, &box_x, &box_y);
                content_mouse_track(box->object, bw, mouse,
                                x - box_x, y - box_y);
                return;
        }

        /* Content related drags handled by now */
        assert(html->drag_type == HTML_DRAG_NONE);

        /* search the box tree for a link, imagemap, form control, or
         * box with scrollbars
         */

        box = html->layout;

        /* Consider the margins of the html page now */
        box_x = box->margin[LEFT];
        box_y = box->margin[TOP];

        /* descend through visible boxes setting more specific values for:
         * box - deepest box at point
         * html_object_box - html object
         * html_object_pos_x - html object
         * html_object_pos_y - html object
         * object - non html object
         * iframe - iframe
         * url - href or imagemap
         * target - href or imagemap or gadget
         * url_box - href or imagemap
         * imagemap - imagemap
         * gadget - gadget
         * gadget_box - gadget
         * gadget_box_x - gadget
         * gadget_box_y - gadget
         * title - title
         * pointer
         *
         * drag_candidate - first box with scroll
         * padding_left - box with scroll
         * padding_right
         * padding_top
         * padding_bottom
         * scrollbar - inside padding box stops decent
         * scroll_mouse_x - inside padding box stops decent
         * scroll_mouse_y - inside padding box stops decent
         *
         * text_box - text box
         * text_box_x - text_box
         */
        do {
                if ((box->style != NULL) &&
                    (css_computed_visibility(box->style) ==
                     CSS_VISIBILITY_HIDDEN)) {
                        continue;
                }

                if (box->node != NULL) {
                        node = box->node;
                }

                if (box->object) {
                        if (content_get_type(box->object) == CONTENT_HTML) {
                                html_object_box = box;
                                html_object_pos_x = box_x;
                                html_object_pos_y = box_y;
                        } else {
                                object = box->object;
                        }
                }

                if (box->iframe) {
                        iframe = box->iframe;
                }

                if (box->href) {
                        url = box->href;
                        target = box->target;
                        url_box = box;
                }

                if (box->usemap) {
                        url = imagemap_get(html, box->usemap,
                                        box_x, box_y, x, y, &target);
                        if (url) {
                                imagemap = true;
                                url_box = box;
                        }
                }

                if (box->gadget) {
                        gadget = box->gadget;
                        gadget_box = box;
                        gadget_box_x = box_x;
                        gadget_box_y = box_y;
                        if (gadget->form)
                                target = gadget->form->target;
                }

                if (box->title) {
                        title = box->title;
                }

                pointer = get_pointer_shape(box, false);

                if ((box->scroll_x != NULL) ||
                    (box->scroll_y != NULL)) {

                        if (drag_candidate == NULL) {
                                drag_candidate = box;
                        }

                        padding_left = box_x +
                                        scrollbar_get_offset(box->scroll_x);
                        padding_right = padding_left + box->padding[LEFT] +
                                        box->width + box->padding[RIGHT];
                        padding_top = box_y +
                                        scrollbar_get_offset(box->scroll_y);
                        padding_bottom = padding_top + box->padding[TOP] +
                                        box->height + box->padding[BOTTOM];

                        if ((x > padding_left) &&
                            (x < padding_right) &&
                            (y > padding_top) &&
                            (y < padding_bottom)) {
                                /* mouse inside padding box */

                                if ((box->scroll_y != NULL) &&
                                                (x > (padding_right -
                                                        SCROLLBAR_WIDTH))) {
                                        /* mouse above vertical box scroll */

                                        scrollbar = box->scroll_y;
                                        scroll_mouse_x = x - (padding_right -
                                                             SCROLLBAR_WIDTH);
                                        scroll_mouse_y = y - padding_top;
                                        break;

                                } else if ((box->scroll_x != NULL) &&
                                                (y > (padding_bottom -
                                                        SCROLLBAR_WIDTH))) {
                                        /* mouse above horizontal box scroll */

                                        scrollbar = box->scroll_x;
                                        scroll_mouse_x = x - padding_left;
                                        scroll_mouse_y = y - (padding_bottom -
                                                        SCROLLBAR_WIDTH);
                                        break;
                                }
                        }
                }

                if (box->text && !box->object) {
                        text_box = box;
                        text_box_x = box_x;
                }
        } while ((box = box_at_point(&html->len_ctx, box, x, y,
                        &box_x, &box_y)) != NULL);

        /* use of box_x, box_y, or content below this point is probably a
         * mistake; they will refer to the last box returned by box_at_point */
        assert(node != NULL);

        if (scrollbar) {
                status = scrollbar_mouse_status_to_message(
                                scrollbar_mouse_action(scrollbar, mouse,
                                                scroll_mouse_x,
                                                scroll_mouse_y));
                pointer = BROWSER_POINTER_DEFAULT;
        } else if (gadget) {
                textarea_mouse_status ta_status;

                switch (gadget->type) {
                case GADGET_SELECT:
                        status = messages_get("FormSelect");
                        pointer = BROWSER_POINTER_MENU;
                        if (mouse & BROWSER_MOUSE_CLICK_1 &&
                            nsoption_bool(core_select_menu)) {
                                html->visible_select_menu = gadget;
                                res = form_open_select_menu(c, gadget,
                                                form_select_menu_callback,
                                                c);
                                if (res != NSERROR_OK) {
                                        NSLOG(netsurf, ERROR,
                                              "%s",
                                              messages_get_errorcode(res));
                                        html->visible_select_menu = NULL;
                                }
                                pointer = BROWSER_POINTER_DEFAULT;
                        } else if (mouse & BROWSER_MOUSE_CLICK_1) {
                                msg_data.select_menu.gadget = gadget;
                                content_broadcast(c, CONTENT_MSG_SELECTMENU,
                                                &msg_data);
                        }
                        break;
                case GADGET_CHECKBOX:
                        status = messages_get("FormCheckbox");
                        if (mouse & BROWSER_MOUSE_CLICK_1) {
                                gadget->selected = !gadget->selected;
                                dom_html_input_element_set_checked(
                                        (dom_html_input_element *)(gadget->node),
                                        gadget->selected);
                                html__redraw_a_box(html, gadget_box);
                        }
                        break;
                case GADGET_RADIO:
                        status = messages_get("FormRadio");
                        if (mouse & BROWSER_MOUSE_CLICK_1)
                                form_radio_set(gadget);
                        break;
                case GADGET_IMAGE:
                        /* This falls through to SUBMIT */
                        if (mouse & BROWSER_MOUSE_CLICK_1) {
                                struct image_input_coords *coords, *oldcoords;
                                /** \todo Find a way to not ignore errors */
                                coords = calloc(1, sizeof(*coords));
                                if (coords == NULL) {
                                        return;
                                }
                                coords->x = x - gadget_box_x;
                                coords->y = y - gadget_box_y;
                                if (dom_node_set_user_data(
                                            gadget->node,
                                            corestring_dom___ns_key_image_coords_node_data,
                                            coords, html__image_coords_dom_user_data_handler,
                                            &oldcoords) != DOM_NO_ERR)
                                        return;
                                free(oldcoords);
                        }
                        /* Fall through */
                case GADGET_SUBMIT:
                        if (gadget->form) {
                                snprintf(status_buffer, sizeof status_buffer,
                                                messages_get("FormSubmit"),
                                                gadget->form->action);
                                status = status_buffer;
                                pointer = get_pointer_shape(gadget_box, false);
                                if (mouse & (BROWSER_MOUSE_CLICK_1 |
                                                BROWSER_MOUSE_CLICK_2))
                                        action = ACTION_SUBMIT;
                        } else {
                                status = messages_get("FormBadSubmit");
                        }
                        break;
                case GADGET_TEXTBOX:
                case GADGET_PASSWORD:
                case GADGET_TEXTAREA:
                        if (gadget->type == GADGET_TEXTAREA)
                                status = messages_get("FormTextarea");
                        else
                                status = messages_get("FormTextbox");

                        if (click && (html->selection_type !=
                                        HTML_SELECTION_TEXTAREA ||
                                        html->selection_owner.textarea !=
                                        gadget_box)) {
                                sel_owner.none = true;
                                html_set_selection(html, HTML_SELECTION_NONE,
                                                sel_owner, true);
                        }

                        ta_status = textarea_mouse_action(gadget->data.text.ta,
                                        mouse, x - gadget_box_x,
                                        y - gadget_box_y);

                        if (ta_status & TEXTAREA_MOUSE_EDITOR) {
                                pointer = get_pointer_shape(gadget_box, false);
                        } else {
                                pointer = BROWSER_POINTER_DEFAULT;
                                status = scrollbar_mouse_status_to_message(
                                                ta_status >> 3);
                        }
                        break;
                case GADGET_HIDDEN:
                        /* not possible: no box generated */
                        break;
                case GADGET_RESET:
                        status = messages_get("FormReset");
                        break;
                case GADGET_FILE:
                        status = messages_get("FormFile");
                        if (mouse & BROWSER_MOUSE_CLICK_1) {
                                msg_data.gadget_click.gadget = gadget;
                                content_broadcast(c, CONTENT_MSG_GADGETCLICK,
                                                &msg_data);
                        }
                        break;
                case GADGET_BUTTON:
                        /* This gadget cannot be activated */
                        status = messages_get("FormButton");
                        break;
                }

        } else if (object && (mouse & BROWSER_MOUSE_MOD_2)) {

                if (mouse & BROWSER_MOUSE_DRAG_2) {
                        msg_data.dragsave.type = CONTENT_SAVE_NATIVE;
                        msg_data.dragsave.content = object;
                        content_broadcast(c, CONTENT_MSG_DRAGSAVE, &msg_data);

                } else if (mouse & BROWSER_MOUSE_DRAG_1) {
                        msg_data.dragsave.type = CONTENT_SAVE_ORIG;
                        msg_data.dragsave.content = object;
                        content_broadcast(c, CONTENT_MSG_DRAGSAVE, &msg_data);
                }

                /* \todo should have a drag-saving object msg */

        } else if (iframe) {
                int pos_x, pos_y;
                float scale = browser_window_get_scale(bw);

                browser_window_get_position(iframe, false, &pos_x, &pos_y);

                if (mouse & BROWSER_MOUSE_CLICK_1 ||
                    mouse & BROWSER_MOUSE_CLICK_2) {
                        browser_window_mouse_click(iframe, mouse,
                                                   (x * scale) - pos_x,
                                                   (y * scale) - pos_y);
                } else {
                        browser_window_mouse_track(iframe, mouse,
                                                   (x * scale) - pos_x,
                                                   (y * scale) - pos_y);
                }
        } else if (html_object_box) {

                if (click && (html->selection_type != HTML_SELECTION_CONTENT ||
                                html->selection_owner.content !=
                                                html_object_box)) {
                        sel_owner.none = true;
                        html_set_selection(html, HTML_SELECTION_NONE,
                                        sel_owner, true);
                }
                if (mouse & BROWSER_MOUSE_CLICK_1 ||
                                mouse & BROWSER_MOUSE_CLICK_2) {
                        content_mouse_action(html_object_box->object,
                                        bw, mouse,
                                        x - html_object_pos_x,
                                        y - html_object_pos_y);
                } else {
                        content_mouse_track(html_object_box->object,
                                        bw, mouse,
                                        x - html_object_pos_x,
                                        y - html_object_pos_y);
                }
        } else if (url) {
                if (nsoption_bool(display_decoded_idn) == true) {
                        res = nsurl_get_utf8(url, &url_s, &url_l);
                        if (res != NSERROR_OK) {
                                /* Unable to obtain a decoded IDN. This is not
                                 *  a fatal error.  Ensure the string pointer
                                 *  is NULL so we use the encoded version.
                                 */
                                url_s = NULL;
                        }
                }

                if (title) {
                        snprintf(status_buffer, sizeof status_buffer, "%s: %s",
                                        url_s ? url_s : nsurl_access(url), title);
                } else {
                        snprintf(status_buffer, sizeof status_buffer, "%s",
                                        url_s ? url_s : nsurl_access(url));
                }

                status = status_buffer;

                if (url_s != NULL)
                        free(url_s);

                pointer = get_pointer_shape(url_box, imagemap);

                if (mouse & BROWSER_MOUSE_CLICK_1 &&
                                mouse & BROWSER_MOUSE_MOD_1) {
                        /* force download of link */
                        browser_window_navigate(bw,
                                url,
                                content_get_url(c),
                                BW_NAVIGATE_DOWNLOAD,
                                NULL,
                                NULL,
                                NULL);

                } else if (mouse & BROWSER_MOUSE_CLICK_2 &&
                                mouse & BROWSER_MOUSE_MOD_1) {
                        msg_data.savelink.url = url;
                        msg_data.savelink.title = title;
                        content_broadcast(c, CONTENT_MSG_SAVELINK, &msg_data);

                } else if (mouse & (BROWSER_MOUSE_CLICK_1 |
                                BROWSER_MOUSE_CLICK_2))
                        action = ACTION_GO;
        } else {
                bool done = false;

                /* frame resizing */
                if (browser_window_frame_resize_start(bw, mouse, x, y,
                                &pointer)) {
                        if (mouse & (BROWSER_MOUSE_DRAG_1 |
                                        BROWSER_MOUSE_DRAG_2)) {
                                status = messages_get("FrameDrag");
                        }
                        done = true;
                }

                /* if clicking in the main page, remove the selection from any
                 * text areas */
                if (!done) {

                        if (click && html->focus_type != HTML_FOCUS_SELF) {
                                union html_focus_owner fo;
                                fo.self = true;
                                html_set_focus(html, HTML_FOCUS_SELF, fo,
                                                true, 0, 0, 0, NULL);
                        }
                        if (click && html->selection_type !=
                                        HTML_SELECTION_SELF) {
                                sel_owner.none = true;
                                html_set_selection(html, HTML_SELECTION_NONE,
                                                sel_owner, true);
                        }

                        if (text_box) {
                                int pixel_offset;
                                size_t idx;

                                font_plot_style_from_css(&html->len_ctx,
                                                text_box->style, &fstyle);

                                guit->layout->position(&fstyle,
                                                       text_box->text,
                                                       text_box->length,
                                                       x - text_box_x,
                                                       &idx,
                                                       &pixel_offset);

                                if (selection_click(&html->sel, mouse,
                                                text_box->byte_offset + idx)) {
                                        /* key presses must be directed at the
                                         * main browser window, paste text
                                         * operations ignored */
                                        html_drag_type drag_type;
                                        union html_drag_owner drag_owner;

                                        if (selection_dragging(&html->sel)) {
                                                drag_type = HTML_DRAG_SELECTION;
                                                drag_owner.no_owner = true;
                                                html_set_drag_type(html,
                                                                drag_type,
                                                                drag_owner,
                                                                NULL);
                                                status = messages_get(
                                                                "Selecting");
                                        }

                                        done = true;
                                }

                        } else if (mouse & BROWSER_MOUSE_PRESS_1) {
                                sel_owner.none = true;
                                selection_clear(&html->sel, true);
                        }

                        if (selection_defined(&html->sel)) {
                                sel_owner.none = false;
                                html_set_selection(html, HTML_SELECTION_SELF,
                                                sel_owner, true);
                        } else if (click && html->selection_type !=
                                        HTML_SELECTION_NONE) {
                                sel_owner.none = true;
                                html_set_selection(html, HTML_SELECTION_NONE,
                                                sel_owner, true);
                        }
                }

                if (!done) {
                        if (title)
                                status = title;

                        if (mouse & BROWSER_MOUSE_DRAG_1) {
                                if (mouse & BROWSER_MOUSE_MOD_2) {
                                        msg_data.dragsave.type =
                                                        CONTENT_SAVE_COMPLETE;
                                        msg_data.dragsave.content = NULL;
                                        content_broadcast(c,
                                                        CONTENT_MSG_DRAGSAVE,
                                                        &msg_data);
                                } else {
                                        if (drag_candidate == NULL) {
                                                browser_window_page_drag_start(
                                                                bw, x, y);
                                        } else {
                                                html_box_drag_start(
                                                                drag_candidate,
                                                                x, y);
                                        }
                                        pointer = BROWSER_POINTER_MOVE;
                                }
                        }
                        else if (mouse & BROWSER_MOUSE_DRAG_2) {
                                if (mouse & BROWSER_MOUSE_MOD_2) {
                                        msg_data.dragsave.type =
                                                        CONTENT_SAVE_SOURCE;
                                        msg_data.dragsave.content = NULL;
                                        content_broadcast(c,
                                                        CONTENT_MSG_DRAGSAVE,
                                                        &msg_data);
                                } else {
                                        if (drag_candidate == NULL) {
                                                browser_window_page_drag_start(
                                                                bw, x, y);
                                        } else {
                                                html_box_drag_start(
                                                                drag_candidate,
                                                                x, y);
                                        }
                                        pointer = BROWSER_POINTER_MOVE;
                                }
                        }
                }
                if (mouse && mouse < BROWSER_MOUSE_MOD_1) {
                        /* ensure key presses still act on the browser window */
                        union html_focus_owner fo;
                        fo.self = true;
                        html_set_focus(html, HTML_FOCUS_SELF, fo,
                                        true, 0, 0, 0, NULL);
                }
        }

        if (!iframe && !html_object_box) {
                msg_data.explicit_status_text = status;
                content_broadcast(c, CONTENT_MSG_STATUS, &msg_data);

                msg_data.pointer = pointer;
                content_broadcast(c, CONTENT_MSG_POINTER, &msg_data);
        }

        /* fire dom click event */
        if (mouse & BROWSER_MOUSE_CLICK_1) {
                fire_dom_event(corestring_dom_click, node, true, true);
        }

        /* deferred actions that can cause this browser_window to be destroyed
         * and must therefore be done after set_status/pointer
         */
        switch (action) {
        case ACTION_SUBMIT:
                res = form_submit(content_get_url(c),
                                  browser_window_find_target(bw, target, mouse),
                                  gadget->form,
                                  gadget);
                break;

        case ACTION_GO:
                res = browser_window_navigate(
                                browser_window_find_target(bw, target, mouse),
                                url,
                                content_get_url(c),
                                BW_NAVIGATE_HISTORY,
                                NULL,
                                NULL,
                                NULL);
                break;

        case ACTION_NONE:
                res = NSERROR_OK;
                break;
        }

        if (res != NSERROR_OK) {
                NSLOG(netsurf, ERROR, "%s", messages_get_errorcode(res));
        }

}


/**
 * Handle keypresses.
 *
 * \param  c    content of type HTML
 * \param  key  The UCS4 character codepoint
 * \return true if key handled, false otherwise
 */

bool html_keypress(struct content *c, uint32_t key)
{
        html_content *html = (html_content *) c;
        struct selection *sel = &html->sel;

        switch (html->focus_type) {
        case HTML_FOCUS_CONTENT:
                return content_keypress(html->focus_owner.content->object, key);

        case HTML_FOCUS_TEXTAREA:
                if (box_textarea_keypress(html, html->focus_owner.textarea, key) == NSERROR_OK) {
                        return true;
                } else {
                        return false;
                }

        default:
                /* Deal with it below */
                break;
        }

        switch (key) {
        case NS_KEY_COPY_SELECTION:
                selection_copy_to_clipboard(sel);
                return true;

        case NS_KEY_CLEAR_SELECTION:
                selection_clear(sel, true);
                return true;

        case NS_KEY_SELECT_ALL:
                selection_select_all(sel);
                return true;

        case NS_KEY_ESCAPE:
                if (selection_defined(sel)) {
                        selection_clear(sel, true);
                        return true;
                }

                /* if there's no selection, leave Escape for the caller */
                return false;
        }

        return false;
}


/**
 * Handle search.
 *
 * \param c content of type HTML
 * \param context front end private data
 * \param flags search flags
 * \param string search string
 */
void
html_search(struct content *c,
            void *context,
            search_flags_t flags,
            const char *string)
{
        html_content *html = (html_content *)c;

        assert(c != NULL);

        if ((string != NULL) &&
            (html->search_string != NULL) &&
            (strcmp(string, html->search_string) == 0) &&
            (html->search != NULL)) {
                /* Continue prev. search */
                search_step(html->search, flags, string);

        } else if (string != NULL) {
                /* New search */
                free(html->search_string);
                html->search_string = strdup(string);
                if (html->search_string == NULL)
                        return;

                if (html->search != NULL) {
                        search_destroy_context(html->search);
                        html->search = NULL;
                }

                html->search = search_create_context(c, CONTENT_HTML, context);

                if (html->search == NULL)
                        return;

                search_step(html->search, flags, string);

        } else {
                /* Clear search */
                html_search_clear(c);

                free(html->search_string);
                html->search_string = NULL;
        }
}


/**
 * Terminate a search.
 *
 * \param  c                    content of type HTML
 */
void html_search_clear(struct content *c)
{
        html_content *html = (html_content *)c;

        assert(c != NULL);

        free(html->search_string);
        html->search_string = NULL;

        if (html->search != NULL) {
                search_destroy_context(html->search);
        }
        html->search = NULL;
}


/**
 * Callback for in-page scrollbars.
 */
void html_overflow_scroll_callback(void *client_data,
                struct scrollbar_msg_data *scrollbar_data)
{
        struct html_scrollbar_data *data = client_data;
        html_content *html = (html_content *)data->c;
        struct box *box = data->box;
        union content_msg_data msg_data;
        html_drag_type drag_type;
        union html_drag_owner drag_owner;

        switch(scrollbar_data->msg) {
        case SCROLLBAR_MSG_MOVED:

                if (html->reflowing == true) {
                        /* Can't redraw during layout, and it will
                         * be redrawn after layout anyway. */
                        break;
                }

                html__redraw_a_box(html, box);
                break;
        case SCROLLBAR_MSG_SCROLL_START:
        {
                struct rect rect = {
                        .x0 = scrollbar_data->x0,
                        .y0 = scrollbar_data->y0,
                        .x1 = scrollbar_data->x1,
                        .y1 = scrollbar_data->y1
                };
                drag_type = HTML_DRAG_SCROLLBAR;
                drag_owner.scrollbar = scrollbar_data->scrollbar;
                html_set_drag_type(html, drag_type, drag_owner, &rect);
        }
                break;
        case SCROLLBAR_MSG_SCROLL_FINISHED:
                drag_type = HTML_DRAG_NONE;
                drag_owner.no_owner = true;
                html_set_drag_type(html, drag_type, drag_owner, NULL);

                msg_data.pointer = BROWSER_POINTER_AUTO;
                content_broadcast(data->c, CONTENT_MSG_POINTER, &msg_data);
                break;
        }
}


/* Documented in html_internal.h */
void html_set_drag_type(html_content *html, html_drag_type drag_type,
                union html_drag_owner drag_owner, const struct rect *rect)
{
        union content_msg_data msg_data;

        assert(html != NULL);

        html->drag_type = drag_type;
        html->drag_owner = drag_owner;

        switch (drag_type) {
        case HTML_DRAG_NONE:
                assert(drag_owner.no_owner == true);
                msg_data.drag.type = CONTENT_DRAG_NONE;
                break;

        case HTML_DRAG_SCROLLBAR:
        case HTML_DRAG_TEXTAREA_SCROLLBAR:
        case HTML_DRAG_CONTENT_SCROLL:
                msg_data.drag.type = CONTENT_DRAG_SCROLL;
                break;

        case HTML_DRAG_SELECTION:
                assert(drag_owner.no_owner == true);
                /* Fall through */
        case HTML_DRAG_TEXTAREA_SELECTION:
        case HTML_DRAG_CONTENT_SELECTION:
                msg_data.drag.type = CONTENT_DRAG_SELECTION;
                break;
        }
        msg_data.drag.rect = rect;

        /* Inform of the content's drag status change */
        content_broadcast((struct content *)html, CONTENT_MSG_DRAG, &msg_data);
}

/* Documented in html_internal.h */
void html_set_focus(html_content *html, html_focus_type focus_type,
                union html_focus_owner focus_owner, bool hide_caret,
                int x, int y, int height, const struct rect *clip)
{
        union content_msg_data msg_data;
        int x_off = 0;
        int y_off = 0;
        struct rect cr;
        bool textarea_lost_focus = html->focus_type == HTML_FOCUS_TEXTAREA &&
                        focus_type != HTML_FOCUS_TEXTAREA;

        assert(html != NULL);

        switch (focus_type) {
        case HTML_FOCUS_SELF:
                assert(focus_owner.self == true);
                if (html->focus_type == HTML_FOCUS_SELF)
                        /* Don't need to tell anyone anything */
                        return;
                break;

        case HTML_FOCUS_CONTENT:
                box_coords(focus_owner.content, &x_off, &y_off);
                break;

        case HTML_FOCUS_TEXTAREA:
                box_coords(focus_owner.textarea, &x_off, &y_off);
                break;
        }

        html->focus_type = focus_type;
        html->focus_owner = focus_owner;

        if (textarea_lost_focus) {
                msg_data.caret.type = CONTENT_CARET_REMOVE;
        } else if (focus_type != HTML_FOCUS_SELF && hide_caret) {
                msg_data.caret.type = CONTENT_CARET_HIDE;
        } else {
                if (clip != NULL) {
                        cr = *clip;
                        cr.x0 += x_off;
                        cr.y0 += y_off;
                        cr.x1 += x_off;
                        cr.y1 += y_off;
                }

                msg_data.caret.type = CONTENT_CARET_SET_POS;
                msg_data.caret.pos.x = x + x_off;
                msg_data.caret.pos.y = y + y_off;
                msg_data.caret.pos.height = height;
                msg_data.caret.pos.clip = (clip == NULL) ? NULL : &cr;
        }

        /* Inform of the content's drag status change */
        content_broadcast((struct content *)html, CONTENT_MSG_CARET, &msg_data);
}

/* Documented in html_internal.h */
void html_set_selection(html_content *html, html_selection_type selection_type,
                union html_selection_owner selection_owner, bool read_only)
{
        union content_msg_data msg_data;
        struct box *box;
        bool changed = false;
        bool same_type = html->selection_type == selection_type;

        assert(html != NULL);

        if ((selection_type == HTML_SELECTION_NONE &&
                        html->selection_type != HTML_SELECTION_NONE) ||
                        (selection_type != HTML_SELECTION_NONE &&
                        html->selection_type == HTML_SELECTION_NONE))
                /* Existance of selection has changed, and we'll need to
                 * inform our owner */
                changed = true;

        /* Clear any existing selection */
        if (html->selection_type != HTML_SELECTION_NONE) {
                switch (html->selection_type) {
                case HTML_SELECTION_SELF:
                        if (same_type)
                                break;
                        selection_clear(&html->sel, true);
                        break;
                case HTML_SELECTION_TEXTAREA:
                        if (same_type && html->selection_owner.textarea ==
                                        selection_owner.textarea)
                                break;
                        box = html->selection_owner.textarea;
                        textarea_clear_selection(box->gadget->data.text.ta);
                        break;
                case HTML_SELECTION_CONTENT:
                        if (same_type && html->selection_owner.content ==
                                        selection_owner.content)
                                break;
                        box = html->selection_owner.content;
                        content_clear_selection(box->object);
                        break;
                default:
                        break;
                }
        }

        html->selection_type = selection_type;
        html->selection_owner = selection_owner;

        if (!changed)
                /* Don't need to report lack of change to owner */
                return;

        /* Prepare msg */
        switch (selection_type) {
        case HTML_SELECTION_NONE:
                assert(selection_owner.none == true);
                msg_data.selection.selection = false;
                break;
        case HTML_SELECTION_SELF:
                assert(selection_owner.none == false);
                /* fall through */
        case HTML_SELECTION_TEXTAREA:
        case HTML_SELECTION_CONTENT:
                msg_data.selection.selection = true;
                break;
        default:
                break;
        }
        msg_data.selection.read_only = read_only;

        /* Inform of the content's selection status change */
        content_broadcast((struct content *)html, CONTENT_MSG_SELECTION,
                        &msg_data);
}