text.c

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/*
 * Copyright 2010 Vincent Sanders <vince@simtec.co.uk>
 *
 * Framebuffer windowing toolkit scrollbar widgets.
 *
 * 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/>.
 */
 
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
 
#include <libnsfb.h>
#include <libnsfb_plot.h>
#include <libnsfb_plot_util.h>
#include <libnsfb_event.h>
 
#include "utils/log.h"
#include "netsurf/browser_window.h"
#include "netsurf/plotters.h"
 
#include "framebuffer/gui.h"
#include "framebuffer/fbtk.h"
#include "framebuffer/font.h"
#include "framebuffer/framebuffer.h"
#include "framebuffer/image_data.h"
 
#include "widget.h"
 
//#define TEXT_WIDGET_BORDER 3 /**< The pixel border round a text widget. */
 
/* Lighten a colour by taking seven eights of each channel's intensity
 * and adding a full eighth
 */
#define brighten_colour(c1)                                     \
        (((((7 * ((c1 >> 16) & 0xff)) >> 3) + 32) << 16) |      \
         ((((7 * ((c1 >> 8) & 0xff)) >> 3) + 32) << 8) |        \
         ((((7 * (c1 & 0xff)) >> 3) + 32) << 0))
 
/* Convert pixels to points, assuming a DPI of 90 */
#define px_to_pt(x) (((x) * 72) / FBTK_DPI)
 
/* Get a font style for a text input */
static inline void
fb_text_font_style(fbtk_widget_t *widget, int *font_height, int *padding,
                plot_font_style_t *font_style)
{
        if (widget->u.text.outline)
                *padding = 1;
        else
                *padding = 0;
 
#ifdef FB_USE_FREETYPE
        *padding += widget->height / 6;
        *font_height = widget->height - *padding - *padding;
#else
        *font_height = FB_FONT_HEIGHT;
        *padding = (widget->height - *padding - *font_height) / 2;
#endif
 
        font_style->family = PLOT_FONT_FAMILY_SANS_SERIF;
        font_style->size = px_to_pt(*font_height * PLOT_STYLE_SCALE);
        font_style->weight = 400;
        font_style->flags = FONTF_NONE;
        font_style->background = widget->bg;
        font_style->foreground = widget->fg;
}
 
/** Text redraw callback.
 *
 * Called when a text widget requires redrawing.
 *
 * @param widget The widget to be redrawn.
 * @param cbi The callback parameters.
 * @return The callback result.
 */
static int
fb_redraw_text(fbtk_widget_t *widget, fbtk_callback_info *cbi )
{
        nsfb_bbox_t bbox;
        nsfb_bbox_t rect;
        fbtk_widget_t *root;
        plot_font_style_t font_style;
        int caret_x, caret_y, caret_h;
        int fh;
        int padding;
        int scroll = 0;
        bool caret = false;
        struct redraw_context ctx = {
                .interactive = true,
                .background_images = true,
                .plot = &fb_plotters
        };
 
        fb_text_font_style(widget, &fh, &padding, &font_style);
 
        if (fbtk_get_caret(widget, &caret_x, &caret_y, &caret_h)) {
                caret = true;
        }
 
        root = fbtk_get_root_widget(widget);
 
        fbtk_get_bbox(widget, &bbox);
 
        rect = bbox;
 
        nsfb_claim(root->u.root.fb, &bbox);
 
        /* clear background */
        if ((widget->bg & 0xFF000000) != 0) {
                /* transparent polygon filling isnt working so fake it */
                nsfb_plot_rectangle_fill(root->u.root.fb, &bbox, widget->bg);
        }
 
        /* widget can have a single pixel outline border */
        if (widget->u.text.outline) {
                rect.x1--;
                rect.y1--;
                nsfb_plot_rectangle(root->u.root.fb, &rect, 1,
                                0x00000000, false, false);
        }
 
        if (widget->u.text.text != NULL) {
                int x = bbox.x0 + padding;
                int y = bbox.y0 + ((fh * 3 + 2) / 4) + padding;
 
#ifdef FB_USE_FREETYPE
                /* Freetype renders text higher */
                y += 1;
#endif
 
                if (caret && widget->width - padding - padding < caret_x) {
                        scroll = (widget->width - padding - padding) - caret_x;
                        x +=  scroll;
                }
 
                /* Call the fb text plotting, baseline is 3/4 down the font */
                ctx.plot->text(&ctx,
                               &font_style,
                               x, y,
                               widget->u.text.text,
                               widget->u.text.len);
        }
 
        if (caret) {
                /* This widget has caret, so render it */
                nsfb_t *nsfb = fbtk_get_nsfb(widget);
                nsfb_bbox_t line;
                nsfb_plot_pen_t pen;
 
                line.x0 = bbox.x0 + caret_x + scroll;
                line.y0 = bbox.y0 + caret_y;
                line.x1 = bbox.x0 + caret_x + scroll;
                line.y1 = bbox.y0 + caret_y + caret_h;
 
                pen.stroke_type = NFSB_PLOT_OPTYPE_SOLID;
                pen.stroke_width = 1;
                pen.stroke_colour = 0xFF0000FF;
 
                nsfb_plot_line(nsfb, &line, &pen);
        }
 
        nsfb_update(root->u.root.fb, &bbox);
 
        return 0;
}
 
/** Text destroy callback.
 *
 * Called when a text widget is destroyed.
 *
 * @param widget The widget being destroyed.
 * @param cbi The callback parameters.
 * @return The callback result.
 */
static int fb_destroy_text(fbtk_widget_t *widget, fbtk_callback_info *cbi)
{
        if ((widget == NULL) || (widget->type != FB_WIDGET_TYPE_TEXT)) {
                return 0;
        }
 
        if (widget->u.text.text != NULL) {
                free(widget->u.text.text);
        }
 
        return 0;
}
 
/** Text button redraw callback.
 *
 * Called when a text widget requires redrawing.
 *
 * @param widget The widget to be redrawn.
 * @param cbi The callback parameters.
 * @return The callback result.
 */
static int
fb_redraw_text_button(fbtk_widget_t *widget, fbtk_callback_info *cbi )
{
        nsfb_bbox_t bbox;
        nsfb_bbox_t rect;
        nsfb_bbox_t line;
        nsfb_plot_pen_t pen;
        plot_font_style_t font_style;
        int fh;
        int border;
        fbtk_widget_t *root = fbtk_get_root_widget(widget);
        struct redraw_context ctx = {
                .interactive = true,
                .background_images = true,
                .plot = &fb_plotters
        };
 
        fb_text_font_style(widget, &fh, &border, &font_style);
 
        pen.stroke_type = NFSB_PLOT_OPTYPE_SOLID;
        pen.stroke_width = 1;
        pen.stroke_colour = brighten_colour(widget->bg);
 
        fbtk_get_bbox(widget, &bbox);
 
        rect = bbox;
        rect.x1--;
        rect.y1--;
 
        nsfb_claim(root->u.root.fb, &bbox);
 
        /* clear background */
        if ((widget->bg & 0xFF000000) != 0) {
                /* transparent polygon filling isnt working so fake it */
                nsfb_plot_rectangle_fill(root->u.root.fb, &rect, widget->bg);
        }
 
        if (widget->u.text.outline) {
                line.x0 = rect.x0;
                line.y0 = rect.y0;
                line.x1 = rect.x0;
                line.y1 = rect.y1;
                nsfb_plot_line(root->u.root.fb, &line, &pen);
                line.x0 = rect.x0;
                line.y0 = rect.y0;
                line.x1 = rect.x1;
                line.y1 = rect.y0;
                nsfb_plot_line(root->u.root.fb, &line, &pen);
                pen.stroke_colour = darken_colour(widget->bg);
                line.x0 = rect.x0;
                line.y0 = rect.y1;
                line.x1 = rect.x1;
                line.y1 = rect.y1;
                nsfb_plot_line(root->u.root.fb, &line, &pen);
                line.x0 = rect.x1;
                line.y0 = rect.y0;
                line.x1 = rect.x1;
                line.y1 = rect.y1;
                nsfb_plot_line(root->u.root.fb, &line, &pen);
        }
 
        if (widget->u.text.text != NULL) {
                /* Call the fb text plotting, baseline is 3/4 down the font */
                ctx.plot->text(&ctx,
                               &font_style,
                               bbox.x0 + border,
                               bbox.y0 + ((fh * 3) / 4) + border,
                               widget->u.text.text,
                               widget->u.text.len);
        }
 
        nsfb_update(root->u.root.fb, &bbox);
 
        return 0;
}
 
static void
fb_text_input_remove_caret_cb(fbtk_widget_t *widget)
{
        int c_x, c_y, c_h;
 
        if (fbtk_get_caret(widget, &c_x, &c_y, &c_h)) {
                fbtk_request_redraw(widget);
        }
}
 
/** Routine called when text events occour in writeable widget.
 *
 * @param widget The widget reciving input events.
 * @param cbi The callback parameters.
 * @return The callback result.
 */
static int
text_input(fbtk_widget_t *widget, fbtk_callback_info *cbi)
{
        int value;
        static fbtk_modifier_type modifier = FBTK_MOD_CLEAR;
        char *temp;
        plot_font_style_t font_style;
        int fh;
        int border;
        bool caret_moved = false;
 
        fb_text_font_style(widget, &fh, &border, &font_style);
 
        if (cbi->event == NULL) {
                /* gain focus */
                if (widget->u.text.text == NULL)
                        widget->u.text.text = calloc(1,1);
 
                return 0;
        }
 
        value = cbi->event->value.keycode;
 
        if (cbi->event->type != NSFB_EVENT_KEY_DOWN) {
                switch (value) {
                case NSFB_KEY_RSHIFT:
                        modifier &= ~FBTK_MOD_RSHIFT;
                        break;
 
                case NSFB_KEY_LSHIFT:
                        modifier &= ~FBTK_MOD_LSHIFT;
                        break;
 
                case NSFB_KEY_RCTRL:
                        modifier &= ~FBTK_MOD_RCTRL;
                        break;
 
                case NSFB_KEY_LCTRL:
                        modifier &= ~FBTK_MOD_LCTRL;
                        break;
 
                default:
                        break;
                }
                return 0;
        }
 
        switch (value) {
        case NSFB_KEY_BACKSPACE:
                if (widget->u.text.idx <= 0)
                        break;
                memmove(widget->u.text.text + widget->u.text.idx - 1,
                                widget->u.text.text + widget->u.text.idx,
                                widget->u.text.len - widget->u.text.idx);
                widget->u.text.idx--;
                widget->u.text.len--;
                widget->u.text.text[widget->u.text.len] = 0;
 
                fb_font_width(&font_style, widget->u.text.text,
                                widget->u.text.len, &widget->u.text.width);
 
                caret_moved = true;
                break;
 
        case NSFB_KEY_RETURN:
                widget->u.text.enter(widget->u.text.pw, widget->u.text.text);
                break;
 
        case NSFB_KEY_RIGHT:
                if (widget->u.text.idx < widget->u.text.len) {
                        if (modifier == FBTK_MOD_CLEAR)
                                widget->u.text.idx++;
                        else
                                widget->u.text.idx = widget->u.text.len;
 
                        caret_moved = true;
                }
                break;
 
        case NSFB_KEY_LEFT:
                if (widget->u.text.idx > 0) {
                        if (modifier == FBTK_MOD_CLEAR)
                                widget->u.text.idx--;
                        else
                                widget->u.text.idx = 0;
 
                        caret_moved = true;
                }
                break;
 
        case NSFB_KEY_HOME:
                if (widget->u.text.idx > 0) {
                        widget->u.text.idx = 0;
 
                        caret_moved = true;
                }
                break;
 
        case NSFB_KEY_END:
                if (widget->u.text.idx < widget->u.text.len) {
                        widget->u.text.idx = widget->u.text.len;
 
                        caret_moved = true;
                }
                break;
 
        case NSFB_KEY_PAGEUP:
        case NSFB_KEY_PAGEDOWN:
        case NSFB_KEY_UP:
        case NSFB_KEY_DOWN:
                /* Not handling any of these correctly yet, but avoid putting
                 * charcters in the text widget when they're pressed. */
                break;
 
        case NSFB_KEY_RSHIFT:
                modifier |= FBTK_MOD_RSHIFT;
                break;
 
        case NSFB_KEY_LSHIFT:
                modifier |= FBTK_MOD_LSHIFT;
                break;
 
        case NSFB_KEY_RCTRL:
                modifier |= FBTK_MOD_RCTRL;
                break;
 
        case NSFB_KEY_LCTRL:
                modifier |= FBTK_MOD_LCTRL;
                break;
 
        default:
                if (modifier & FBTK_MOD_LCTRL || modifier & FBTK_MOD_RCTRL) {
                        /* CTRL pressed, don't enter any text */
                        if (value == NSFB_KEY_u) {
                                /* CTRL+U: clear writable */
                                widget->u.text.idx = 0;
                                widget->u.text.len = 0;
                                widget->u.text.text[widget->u.text.len] = '\0';
                                widget->u.text.width = 0;
                                caret_moved = true;
                        }
                        break;
                }
 
                /* allow for new character and null */
                temp = realloc(widget->u.text.text, widget->u.text.len + 2);
                if (temp == NULL) {
                        break;
                }
 
                widget->u.text.text = temp;
                memmove(widget->u.text.text + widget->u.text.idx + 1,
                                widget->u.text.text + widget->u.text.idx,
                                widget->u.text.len - widget->u.text.idx);
                widget->u.text.text[widget->u.text.idx] =
                                fbtk_keycode_to_ucs4(value, modifier);
                widget->u.text.idx++;
                widget->u.text.len++;
                widget->u.text.text[widget->u.text.len] = '\0';
 
                fb_font_width(&font_style, widget->u.text.text,
                                widget->u.text.len, &widget->u.text.width);
                caret_moved = true;
                break;
        }
 
        if (caret_moved) {
                fb_font_width(&font_style, widget->u.text.text,
                                widget->u.text.idx, &widget->u.text.idx_offset);
                fbtk_set_caret(widget, true,
                                widget->u.text.idx_offset + border,
                                border,
                                widget->height - border - border,
                                fb_text_input_remove_caret_cb);
        }
 
        fbtk_request_redraw(widget);
 
        return 0;
}
 
/** Routine called when click events occour in writeable widget.
 *
 * @param widget The widget reciving click events.
 * @param cbi The callback parameters.
 * @return The callback result.
 */
static int
text_input_click(fbtk_widget_t *widget, fbtk_callback_info *cbi)
{
        plot_font_style_t font_style;
        int fh;
        int border;
        size_t idx;
 
        fb_text_font_style(widget, &fh, &border, &font_style);
 
        widget->u.text.idx = widget->u.text.len;
 
        fb_font_position(&font_style, widget->u.text.text,
                        widget->u.text.len, cbi->x - border,
                        &idx,
                        &widget->u.text.idx_offset);
        widget->u.text.idx = idx;
        fbtk_set_caret(widget, true,
                        widget->u.text.idx_offset + border,
                        border,
                        widget->height - border - border,
                        fb_text_input_remove_caret_cb);
 
        fbtk_request_redraw(widget);
 
        return 0;
}
 
/** Routine called when "stripped of focus" event occours for writeable widget.
 *
 * @param widget The widget reciving "stripped of focus" event.
 * @param cbi The callback parameters.
 * @return The callback result.
 */
static int
text_input_strip_focus(fbtk_widget_t *widget, fbtk_callback_info *cbi)
{
        fbtk_set_caret(widget, false, 0, 0, 0, NULL);
 
        return 0;
}
 
/* exported function documented in fbtk.h */
void
fbtk_writable_text(fbtk_widget_t *widget, fbtk_enter_t enter, void *pw)
{
        widget->u.text.enter = enter;
        widget->u.text.pw = pw;
 
        fbtk_set_handler(widget, FBTK_CBT_INPUT, text_input, widget);
}
 
/* exported function documented in fbtk.h */
void
fbtk_set_text(fbtk_widget_t *widget, const char *text)
{
        plot_font_style_t font_style;
        int c_x, c_y, c_h;
        int fh;
        int border;
 
        if ((widget == NULL) || (widget->type != FB_WIDGET_TYPE_TEXT))
                return;
        if (widget->u.text.text != NULL) {
                if (strcmp(widget->u.text.text, text) == 0)
                        return; /* text is being set to the same thing */
                free(widget->u.text.text);
        }
        widget->u.text.text = strdup(text);
        widget->u.text.len = strlen(text);
        widget->u.text.idx = widget->u.text.len;
 
 
        fb_text_font_style(widget, &fh, &border, &font_style);
        fb_font_width(&font_style, widget->u.text.text,
                        widget->u.text.len, &widget->u.text.width);
        fb_font_width(&font_style, widget->u.text.text,
                        widget->u.text.idx, &widget->u.text.idx_offset);
 
        if (fbtk_get_caret(widget, &c_x, &c_y, &c_h)) {
                /* Widget has caret; move it to end of new string */
                fbtk_set_caret(widget, true,
                                widget->u.text.idx_offset + border,
                                border,
                                widget->height - border - border,
                                fb_text_input_remove_caret_cb);
        }
 
        fbtk_request_redraw(widget);
}
 
/* exported function documented in fbtk.h */
fbtk_widget_t *
fbtk_create_text(fbtk_widget_t *parent,
                 int x,
                 int y,
                 int width,
                 int height,
                 colour bg,
                 colour fg,
                 bool outline)
{
        fbtk_widget_t *neww;
 
        neww = fbtk_widget_new(parent, FB_WIDGET_TYPE_TEXT, x, y, width, height);
        neww->fg = fg;
        neww->bg = bg;
        neww->mapped = true;
        neww->u.text.outline = outline;
 
        fbtk_set_handler(neww, FBTK_CBT_REDRAW, fb_redraw_text, NULL);
        fbtk_set_handler(neww, FBTK_CBT_DESTROY, fb_destroy_text, NULL);
 
        return neww;
}
 
/* exported function documented in fbtk.h */
fbtk_widget_t *
fbtk_create_writable_text(fbtk_widget_t *parent,
                          int x,
                          int y,
                          int width,
                          int height,
                          colour bg,
                          colour fg,
                          bool outline,
                          fbtk_enter_t enter,
                          void *pw)
{
        fbtk_widget_t *neww;
 
        neww = fbtk_widget_new(parent, FB_WIDGET_TYPE_TEXT, x, y, width, height);
        neww->fg = fg;
        neww->bg = bg;
        neww->mapped = true;
 
        neww->u.text.outline = outline;
        neww->u.text.enter = enter;
        neww->u.text.pw = pw;
 
        fbtk_set_handler(neww, FBTK_CBT_REDRAW, fb_redraw_text, NULL);
        fbtk_set_handler(neww, FBTK_CBT_DESTROY, fb_destroy_text, NULL);
        fbtk_set_handler(neww, FBTK_CBT_CLICK, text_input_click, pw);
        fbtk_set_handler(neww, FBTK_CBT_STRIP_FOCUS, text_input_strip_focus, NULL);
        fbtk_set_handler(neww, FBTK_CBT_INPUT, text_input, neww);
 
        return neww;
}
 
/* exported function documented in fbtk.h */
fbtk_widget_t *
fbtk_create_text_button(fbtk_widget_t *parent,
                        int x,
                        int y,
                        int width,
                        int height,
                        colour bg,
                        colour fg,
                        fbtk_callback click,
                        void *pw)
{
        fbtk_widget_t *neww;
 
        neww = fbtk_widget_new(parent, FB_WIDGET_TYPE_TEXT, x, y, width, height);
        neww->fg = fg;
        neww->bg = bg;
        neww->mapped = true;
 
        neww->u.text.outline = true;
 
        fbtk_set_handler(neww, FBTK_CBT_REDRAW, fb_redraw_text_button, NULL);
        fbtk_set_handler(neww, FBTK_CBT_DESTROY, fb_destroy_text, NULL);
        fbtk_set_handler(neww, FBTK_CBT_CLICK, click, pw);
        fbtk_set_handler(neww, FBTK_CBT_POINTERENTER, fbtk_set_ptr, &hand_image);
 
        return neww;
}
 
/*
 * Local Variables:
 * c-basic-offset:8
 * End:
 */