netsurf/render/html_redraw.c

1715 lines
49 KiB
C

/*
* Copyright 2004-2008 James Bursa <bursa@users.sourceforge.net>
* Copyright 2004-2007 John M Bell <jmb202@ecs.soton.ac.uk>
* Copyright 2004-2007 Richard Wilson <info@tinct.net>
* Copyright 2005-2006 Adrian Lees <adrianl@users.sourceforge.net>
* Copyright 2006 Rob Kendrick <rjek@netsurf-browser.org>
* Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
*
* 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
* Redraw of a CONTENT_HTML (implementation).
*/
#include <assert.h>
#include <stdbool.h>
#include <string.h>
#include "utils/config.h"
#include "content/content.h"
#include "css/css.h"
#include "desktop/gui.h"
#include "desktop/plotters.h"
#include "desktop/knockout.h"
#include "desktop/selection.h"
#include "desktop/textinput.h"
#include "desktop/options.h"
#include "render/box.h"
#include "render/font.h"
#include "render/form.h"
#include "render/layout.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/utils.h"
static bool html_redraw_box(struct box *box,
int x, int y,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
float scale, colour current_background_color,
int inline_depth);
static bool html_redraw_box_children(struct box *box,
int x_parent, int y_parent,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
float scale, colour current_background_color);
static bool html_redraw_text_box(struct box *box, int x, int y,
int x0, int y0, int x1, int y1,
float scale, colour current_background_color);
static bool html_redraw_caret(struct caret *caret,
colour current_background_color, float scale);
static bool html_redraw_borders(struct box *box, int x_parent, int y_parent,
int padding_width, int padding_height, float scale);
static bool html_redraw_border_plot(int i, int *p, colour c,
css_border_style style, int thickness);
static colour html_redraw_darker(colour c);
static colour html_redraw_lighter(colour c);
static colour html_redraw_aa(colour c0, colour c1);
static bool html_redraw_checkbox(int x, int y, int width, int height,
bool selected);
static bool html_redraw_radio(int x, int y, int width, int height,
bool selected);
static bool html_redraw_file(int x, int y, int width, int height,
struct box *box, float scale, colour background_colour);
static bool html_redraw_background(int x, int y, struct box *box, float scale,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
colour *background_colour, struct box *background);
static bool html_redraw_text_decoration(struct box *box,
int x_parent, int y_parent, float scale,
colour background_colour);
static bool html_redraw_text_decoration_inline(struct box *box, int x, int y,
float scale, colour colour, float ratio);
static bool html_redraw_text_decoration_block(struct box *box, int x, int y,
float scale, colour colour, float ratio);
static bool html_redraw_scrollbars(struct box *box, float scale,
int x, int y, int padding_width, int padding_height,
colour background_colour);
bool html_redraw_debug = false;
/**
* Draw a CONTENT_HTML using the current set of plotters (plot).
*
* \param c content of type CONTENT_HTML
* \param x coordinate for top-left of redraw
* \param y coordinate for top-left of redraw
* \param width available width (not used for HTML redraw)
* \param height available height (not used for HTML redraw)
* \param clip_x0 clip rectangle
* \param clip_y0 clip rectangle
* \param clip_x1 clip rectangle
* \param clip_y1 clip rectangle
* \param scale scale for redraw
* \param background_colour the background colour
* \return true if successful, false otherwise
*
* x, y, clip_[xy][01] are in target coordinates.
*/
bool html_redraw(struct content *c, int x, int y,
int width, int height,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
float scale, unsigned long background_colour)
{
struct box *box;
bool result;
box = c->data.html.layout;
assert(box);
knockout_plot_start(&plot);
/* clear to background colour */
plot.clip(clip_x0, clip_y0, clip_x1, clip_y1);
if (c->data.html.background_colour != TRANSPARENT)
background_colour = c->data.html.background_colour;
plot.clg(background_colour);
result = html_redraw_box(box, x, y,
clip_x0, clip_y0, clip_x1, clip_y1,
scale, background_colour, 0);
knockout_plot_end();
return result;
}
/**
* Recursively draw a box.
*
* \param box box to draw
* \param x_parent coordinate of parent box
* \param y_parent coordinate of parent box
* \param clip_x0 clip rectangle
* \param clip_y0 clip rectangle
* \param clip_x1 clip rectangle
* \param clip_y1 clip rectangle
* \param scale scale for redraw
* \param current_background_color background colour under this box
* \param inline_depth depth of nested inlines inside an inline container
* \return true if successful, false otherwise
*
* x, y, clip_[xy][01] are in target coordinates.
*/
bool html_redraw_box(struct box *box,
int x_parent, int y_parent,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
float scale, colour current_background_color,
int inline_depth)
{
int x, y;
int width, height;
int padding_left, padding_top, padding_width, padding_height;
int border_left, border_top, border_right, border_bottom;
int x0, y0, x1, y1;
int x_scrolled, y_scrolled;
struct box *bg_box = NULL;
/* avoid trivial FP maths */
if (scale == 1.0) {
x = x_parent + box->x;
y = y_parent + box->y;
width = box->width;
height = box->height;
padding_left = box->padding[LEFT];
padding_top = box->padding[TOP];
padding_width = padding_left + box->width + box->padding[RIGHT];
padding_height = padding_top + box->height +
box->padding[BOTTOM];
border_left = box->border[LEFT];
border_top = box->border[TOP];
border_right = box->border[RIGHT];
border_bottom = box->border[BOTTOM];
} else {
x = (x_parent + box->x) * scale;
y = (y_parent + box->y) * scale;
width = box->width * scale;
height = box->height * scale;
/* left and top padding values are normally zero,
* so avoid trivial FP maths */
padding_left = box->padding[LEFT] ? box->padding[LEFT] * scale
: 0;
padding_top = box->padding[TOP] ? box->padding[TOP] * scale
: 0;
padding_width = (box->padding[LEFT] + box->width +
box->padding[RIGHT]) * scale;
padding_height = (box->padding[TOP] + box->height +
box->padding[BOTTOM]) * scale;
border_left = box->border[LEFT] * scale;
border_top = box->border[TOP] * scale;
border_right = box->border[RIGHT] * scale;
border_bottom = box->border[BOTTOM] * scale;
}
/* calculate rectangle covering this box and descendants */
if (box->style && box->style->overflow != CSS_OVERFLOW_VISIBLE) {
x0 = x - border_left;
y0 = y - border_top;
x1 = x + padding_width + border_right;
y1 = y + padding_height + border_bottom;
} else {
x0 = x + box->descendant_x0 * scale;
y0 = y + box->descendant_y0 * scale;
x1 = x + box->descendant_x1 * scale + 1;
y1 = y + box->descendant_y1 * scale + 1;
}
/* return if the rectangle is completely outside the clip rectangle */
if (clip_y1 < y0 || y1 < clip_y0 || clip_x1 < x0 || x1 < clip_x0)
return ((!plot.group_end) || (plot.group_end()));
/* if visibility is hidden render children only */
if (box->style && box->style->visibility == CSS_VISIBILITY_HIDDEN) {
if ((plot.group_start) && (!plot.group_start("hidden box")))
return false;
if (!html_redraw_box_children(box, x_parent, y_parent,
x0, y0, x1, y1, scale,
current_background_color))
return false;
return ((!plot.group_end) || (plot.group_end()));
}
if ((plot.group_start) && (!plot.group_start("vis box")))
return false;
/* dotted debug outlines */
if (html_redraw_debug) {
if (!plot.rectangle(x, y, padding_width, padding_height,
1, 0x0000ff, true, false))
return false;
if (!plot.rectangle(x + padding_left, y + padding_top,
width, height, 1, 0xff0000, true, false))
return false;
if (!plot.rectangle(x - (box->border[LEFT] +
box->margin[LEFT]) * scale,
y - (box->border[TOP] +
box->margin[TOP]) * scale,
padding_width + (box->border[LEFT] +
box->margin[LEFT] + box->border[RIGHT] +
box->margin[RIGHT]) * scale,
padding_height + (box->border[TOP] +
box->margin[TOP] + box->border[BOTTOM] +
box->margin[BOTTOM]) * scale,
1, 0x00ffff, true, false))
return false;
}
if (box->type == BOX_BLOCK || box->type == BOX_INLINE_BLOCK ||
box->type == BOX_TABLE_CELL || box->object) {
/* find intersection of clip rectangle and box */
if (x0 < clip_x0) x0 = clip_x0;
if (y0 < clip_y0) y0 = clip_y0;
if (clip_x1 < x1) x1 = clip_x1;
if (clip_y1 < y1) y1 = clip_y1;
/* no point trying to draw 0-width/height boxes */
if (x0 == x1 || y0 == y1)
/* not an error */
return ((!plot.group_end) || (plot.group_end()));
/* clip to it */
if (!plot.clip(x0, y0, x1, y1))
return false;
} else {
/* clip box unchanged */
x0 = clip_x0;
y0 = clip_y0;
x1 = clip_x1;
y1 = clip_y1;
}
/* background colour and image */
/* Thanks to backwards compatibility, CSS defines the following:
*
* + If the box is for the root element and it has a background,
* use that (and then process the body box with no special case)
* + If the box is for the root element and it has no background,
* then use the background (if any) from the body element as if
* it were specified on the root. Then, when the box for the body
* element is processed, ignore the background.
* + For any other box, just use its own styling.
*/
if (!box->parent) {
/* Root box */
if (box->style &&
(box->style->background_color != TRANSPARENT ||
box->background)) {
/* With its own background */
bg_box = box;
} else if (!box->style ||
(box->style->background_color == TRANSPARENT &&
!box->background)) {
/* Without its own background */
if (box->children && box->children->style &&
(box->children->style->background_color !=
TRANSPARENT ||
box->children->background)) {
/* But body has one, so use that */
bg_box = box->children;
}
}
} else if (box->parent && !box->parent->parent) {
/* Body box */
if (box->style &&
(box->style->background_color != TRANSPARENT ||
box->background)) {
/* With a background */
if (box->parent->style &&
(box->parent->style->background_color !=
TRANSPARENT ||
box->parent->background)) {
/* Root has own background; process normally */
bg_box = box;
}
}
} else {
/* Any other box */
bg_box = box;
}
/* bg_box == NULL implies that this box should not have
* its background rendered. Otherwise filter out linebreaks,
* optimize away non-differing inlines, only plot background
* for BOX_TEXT it's in an inline and ensure the bg_box
* has something worth rendering */
if (bg_box && (bg_box->style && bg_box->type != BOX_BR &&
(bg_box->type != BOX_INLINE ||
bg_box->style != bg_box->parent->parent->style)) &&
(bg_box->type != BOX_TEXT ||
(bg_box->type == BOX_TEXT && inline_depth > 0)) &&
((bg_box->style->background_color != TRANSPARENT) ||
(bg_box->background))) {
/* find intersection of clip box and border edge */
int px0 = x - border_left < x0 ? x0 : x - border_left;
int py0 = y - border_top < y0 ? y0 : y - border_top;
int px1 = x + padding_width + border_right < x1 ?
x + padding_width + border_right : x1;
int py1 = y + padding_height + border_bottom < y1 ?
y + padding_height + border_bottom : y1;
/* valid clipping rectangles only */
if ((px0 < px1) && (py0 < py1)) {
/* plot background */
if (!html_redraw_background(x, y, box, scale,
px0, py0, px1, py1,
&current_background_color, bg_box))
return false;
/* restore previous graphics window */
if (!plot.clip(x0, y0, x1, y1))
return false;
}
}
/* borders */
if (box->style && box->type != BOX_TEXT &&
(border_top || border_right ||
border_bottom || border_left))
if (!html_redraw_borders(box, x_parent, y_parent,
padding_width, padding_height,
scale))
return false;
/* clip to the padding edge for boxes with overflow hidden or scroll */
if (box->style && box->style->overflow != CSS_OVERFLOW_VISIBLE) {
x0 = x;
y0 = y;
x1 = x + padding_width;
y1 = y + padding_height;
if (x0 < clip_x0) x0 = clip_x0;
if (y0 < clip_y0) y0 = clip_y0;
if (clip_x1 < x1) x1 = clip_x1;
if (clip_y1 < y1) y1 = clip_y1;
if (x1 <= x0 || y1 <= y0)
return ((!plot.group_end) || (plot.group_end()));
if (box->type == BOX_BLOCK || box->type == BOX_INLINE_BLOCK ||
box->type == BOX_TABLE_CELL || box->object) {
if (!plot.clip(x0, y0, x1, y1))
return false;
}
}
/* text decoration */
if (box->type != BOX_TEXT && box->style &&
box->style->text_decoration !=
CSS_TEXT_DECORATION_NONE)
if (!html_redraw_text_decoration(box, x_parent, y_parent,
scale, current_background_color))
return false;
if (box->object) {
x_scrolled = x - box->scroll_x * scale;
y_scrolled = y - box->scroll_y * scale;
if (!content_redraw(box->object,
x_scrolled + padding_left,
y_scrolled + padding_top,
width, height, x0, y0, x1, y1, scale,
current_background_color))
return false;
} else if (box->gadget && box->gadget->type == GADGET_CHECKBOX) {
if (!html_redraw_checkbox(x + padding_left, y + padding_top,
width, height,
box->gadget->selected))
return false;
} else if (box->gadget && box->gadget->type == GADGET_RADIO) {
if (!html_redraw_radio(x + padding_left, y + padding_top,
width, height,
box->gadget->selected))
return false;
} else if (box->gadget && box->gadget->type == GADGET_FILE) {
if (!html_redraw_file(x + padding_left, y + padding_top,
width, height, box, scale,
current_background_color))
return false;
} else if (box->text) {
if (!html_redraw_text_box(box, x, y, x0, y0, x1, y1,
scale, current_background_color))
return false;
} else {
if (!html_redraw_box_children(box, x_parent, y_parent,
x0, y0, x1, y1, scale,
current_background_color))
return false;
}
/* list marker */
if (box->list_marker)
if (!html_redraw_box(box->list_marker,
x_parent + box->x - box->scroll_x,
y_parent + box->y - box->scroll_y,
clip_x0, clip_y0, clip_x1, clip_y1,
scale, current_background_color, 0))
return false;
/* scrollbars */
if (box->style && box->type != BOX_BR && box->type != BOX_INLINE &&
(box->style->overflow == CSS_OVERFLOW_SCROLL ||
box->style->overflow == CSS_OVERFLOW_AUTO))
if (!html_redraw_scrollbars(box, scale, x, y,
padding_width, padding_height,
current_background_color))
return false;
if (box->type == BOX_BLOCK || box->type == BOX_INLINE_BLOCK ||
box->type == BOX_TABLE_CELL || box->object)
if (!plot.clip(clip_x0, clip_y0, clip_x1, clip_y1))
return false;
return ((!plot.group_end) || (plot.group_end()));
}
/**
* Draw the various children of a box.
*
* \param box box to draw
* \param x_parent coordinate of parent box
* \param y_parent coordinate of parent box
* \param clip_x0 clip rectangle
* \param clip_y0 clip rectangle
* \param clip_x1 clip rectangle
* \param clip_y1 clip rectangle
* \param scale scale for redraw
* \param current_background_color background colour under this box
* \return true if successful, false otherwise
*/
bool html_redraw_box_children(struct box *box,
int x_parent, int y_parent,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
float scale, colour current_background_color)
{
int inline_depth = 0;
struct box *c;
for (c = box->children; c; c = c->next) {
if (c->type == BOX_INLINE)
inline_depth++;
else if (c->type == BOX_INLINE_END)
inline_depth--;
if (c->type != BOX_FLOAT_LEFT && c->type != BOX_FLOAT_RIGHT)
if (!html_redraw_box(c,
x_parent + box->x - box->scroll_x,
y_parent + box->y - box->scroll_y,
clip_x0, clip_y0, clip_x1, clip_y1,
scale, current_background_color,
inline_depth))
return false;
}
for (c = box->float_children; c; c = c->next_float)
if (!html_redraw_box(c,
x_parent + box->x - box->scroll_x,
y_parent + box->y - box->scroll_y,
clip_x0, clip_y0, clip_x1, clip_y1,
scale, current_background_color, 0))
return false;
return true;
}
/**
* Redraw the text content of a box, possibly partially highlighted
* because the text has been selected, or matches a search operation.
*
* \param box box with text content
* \param x x co-ord of box
* \param y y co-ord of box
* \param x0 current clip rectangle
* \param y0
* \param x1
* \param y1
* \param scale current scale setting (1.0 = 100%)
* \param current_background_color
* \return true iff successful and redraw should proceed
*/
bool html_redraw_text_box(struct box *box, int x, int y,
int x0, int y0, int x1, int y1,
float scale, colour current_background_color)
{
bool excluded = (box->object != NULL);
struct rect clip;
clip.x0 = x0;
clip.y0 = y0;
clip.x1 = x1;
clip.y1 = y1;
if (!text_redraw(box->text, box->length, box->byte_offset,
box->space, box->style, x, y,
&clip, box->height, scale,
current_background_color, excluded))
return false;
/* does this textbox contain the ghost caret? */
if (ghost_caret.defined && box == ghost_caret.text_box) {
if (!html_redraw_caret(&ghost_caret, current_background_color, scale))
return false;
}
return true;
}
/**
* Redraw a short text string, complete with highlighting
* (for selection/search) and ghost caret
*
* \param utf8_text pointer to UTF-8 text string
* \param utf8_len length of string, in bytes
* \param offset byte offset within textual representation
* \param space indicates whether string is followed by a space
* \param style text style to use
* \param x x ordinate at which to plot text
* \param y y ordinate at which to plot text
* \param clip pointer to current clip rectangle
* \param height height of text string
* \param scale current display scale (1.0 = 100%)
* \param current_background_color
* \param excluded exclude this text string from the selection
* \return true iff successful and redraw should proceed
*/
bool text_redraw(const char *utf8_text, size_t utf8_len,
size_t offset, bool space, struct css_style *style,
int x, int y, struct rect *clip,
int height,
float scale, colour current_background_color,
bool excluded)
{
bool highlighted = false;
/* is this box part of a selection? */
if (!excluded && current_redraw_browser) {
unsigned len = utf8_len + (space ? 1 : 0);
unsigned start_idx;
unsigned end_idx;
/* first try the browser window's current selection */
if (selection_defined(current_redraw_browser->sel) &&
selection_highlighted(current_redraw_browser->sel,
offset, offset + len, &start_idx, &end_idx)) {
highlighted = true;
}
/* what about the current search operation, if any? */
if (!highlighted &&
search_current_window == current_redraw_browser->window &&
gui_search_term_highlighted(current_redraw_browser->window,
offset, offset + len, &start_idx, &end_idx)) {
highlighted = true;
}
/* \todo make search terms visible within selected text */
if (highlighted) {
unsigned endtxt_idx = end_idx;
colour hfore_col, hback_col;
bool clip_changed = false;
bool text_visible = true;
int startx, endx;
if (end_idx > utf8_len) {
/* adjust for trailing space, not present in utf8_text */
assert(end_idx == utf8_len + 1);
endtxt_idx = utf8_len;
}
if (!nsfont_width(style, utf8_text, start_idx, &startx))
startx = 0;
if (!nsfont_width(style, utf8_text, endtxt_idx, &endx))
endx = 0;
/* is there a trailing space that should be highlighted as well? */
if (end_idx > utf8_len) {
int spc_width;
/* \todo is there a more elegant/efficient solution? */
if (nsfont_width(style, " ", 1, &spc_width))
endx += spc_width;
}
if (scale != 1.0) {
startx *= scale;
endx *= scale;
}
/* draw any text preceding highlighted portion */
if (start_idx > 0 &&
!plot.text(x, y + (int) (height * 0.75 * scale),
style, utf8_text, start_idx,
current_background_color,
/*print_text_black ? 0 :*/ style->color))
return false;
/* decide whether highlighted portion is to be white-on-black or
black-on-white */
if ((current_background_color & 0x808080) == 0x808080)
hback_col = 0;
else
hback_col = 0xffffff;
hfore_col = hback_col ^ 0xffffff;
/* highlighted portion */
if (!plot.fill(x + startx, y, x + endx, y + height * scale,
hback_col))
return false;
if (start_idx > 0) {
int px0 = max(x + startx, clip->x0);
int px1 = min(x + endx, clip->x1);
if (px0 < px1) {
if (!plot.clip(px0, clip->y0, px1, clip->y1))
return false;
clip_changed = true;
} else
text_visible = false;
}
if (text_visible &&
!plot.text(x, y + (int) (height * 0.75 * scale),
style, utf8_text, endtxt_idx,
hback_col, hfore_col))
return false;
/* draw any text succeeding highlighted portion */
if (endtxt_idx < utf8_len) {
int px0 = max(x + endx, clip->x0);
if (px0 < clip->x1) {
if (!plot.clip(px0, clip->y0, clip->x1, clip->y1))
return false;
clip_changed = true;
if (!plot.text(x, y + (int) (height * 0.75 * scale),
style, utf8_text, utf8_len,
current_background_color,
/*print_text_black ? 0 :*/ style->color))
return false;
}
}
if (clip_changed &&
!plot.clip(clip->x0, clip->y0, clip->x1, clip->y1))
return false;
}
}
if (!highlighted) {
if (!plot.text(x, y + (int) (height * 0.75 * scale),
style, utf8_text, utf8_len,
current_background_color,
/*print_text_black ? 0 :*/ style->color))
return false;
}
return true;
}
/**
* Draw text caret.
*
* \param c structure describing text caret
* \param current_background_color background colour under the caret
* \param scale current scale setting (1.0 = 100%)
* \return true iff successful and redraw should proceed
*/
bool html_redraw_caret(struct caret *c, colour current_background_color,
float scale)
{
colour caret_color = 0x808080; /* todo - choose a proper colour */
int xc = c->x, y = c->y;
int h = c->height - 1;
int w = (h + 7) / 8;
return (plot.line(xc * scale, y * scale,
xc * scale, (y + h) * scale,
0, caret_color, false, false) &&
plot.line((xc - w) * scale, y * scale,
(xc + w) * scale, y * scale,
0, caret_color, false, false) &&
plot.line((xc - w) * scale, (y + h) * scale,
(xc + w) * scale, (y + h) * scale,
0, caret_color, false, false));
}
/**
* Draw borders for a box.
*
* \param box box to draw
* \param x_parent coordinate of left padding edge of parent of box
* \param y_parent coordinate of top padding edge of parent of box
* \param padding_width width of padding box
* \param padding_height height of padding box
* \param scale scale for redraw
* \return true if successful, false otherwise
*/
bool html_redraw_borders(struct box *box, int x_parent, int y_parent,
int padding_width, int padding_height, float scale)
{
int top = box->border[TOP];
int right = box->border[RIGHT];
int bottom = box->border[BOTTOM];
int left = box->border[LEFT];
if (scale != 1.0) {
top *= scale;
right *= scale;
bottom *= scale;
left *= scale;
}
assert(box->style);
if (box->type == BOX_INLINE && !box->object && !box->gadget &&
!box->text) {
int padding_height = (box->padding[TOP] + box->height +
box->padding[BOTTOM]) * scale;
for (struct box *c = box; c; c = c->next) {
int x = (x_parent + c->x) * scale;
int y = y_parent + c->y;
int padding_width = c->width;
if (c != box)
y -= box->padding[TOP];
if (c == box)
padding_width += box->padding[LEFT];
if (!box->inline_end || c == box->inline_end)
padding_width += box->padding[RIGHT];
if (scale != 1) {
y *= scale;
padding_width *= scale;
}
int p[20] = {
x, y,
x - left, y - top,
x + padding_width + right, y - top,
x + padding_width, y,
x + padding_width, y + padding_height,
x + padding_width + right,
y + padding_height + bottom,
x - left, y + padding_height + bottom,
x, y + padding_height,
x, y,
x - left, y - top
};
if (box->border[LEFT] && c == box)
html_redraw_border_plot(LEFT, p,
box->style->border[LEFT].color,
box->style->border[LEFT].style,
box->border[LEFT] * scale);
if (box->border[TOP])
html_redraw_border_plot(TOP, p,
box->style->border[TOP].color,
box->style->border[TOP].style,
box->border[TOP] * scale);
if (box->border[BOTTOM])
html_redraw_border_plot(BOTTOM, p,
box->style->border[BOTTOM].
color,
box->style->border[BOTTOM].
style,
box->border[BOTTOM] * scale);
if (box->border[RIGHT] && (!box->inline_end ||
c == box->inline_end))
html_redraw_border_plot(RIGHT, p,
box->style->border[RIGHT].color,
box->style->border[RIGHT].style,
box->border[RIGHT] * scale);
if (!box->inline_end || c == box->inline_end)
break;
}
} else {
int x = (x_parent + box->x) * scale;
int y = (y_parent + box->y) * scale;
int p[20] = {
x, y,
x - left, y - top,
x + padding_width + right, y - top,
x + padding_width, y,
x + padding_width, y + padding_height,
x + padding_width + right, y + padding_height + bottom,
x - left, y + padding_height + bottom,
x, y + padding_height,
x, y,
x - left, y - top
};
for (unsigned int i = 0; i != 4; i++) {
if (box->border[i] == 0)
continue;
if (!html_redraw_border_plot(i, p,
box->style->border[i].color,
box->style->border[i].style,
box->border[i] * scale))
return false;
}
}
return true;
}
/**
* Draw one border.
*
* \param i index of border (TOP, RIGHT, BOTTOM, LEFT)
* \param p array of precomputed border vertices
* \param c colour for border
* \param style border line style
* \param thickness border thickness
* \return true if successful, false otherwise
*/
bool html_redraw_border_plot(int i, int *p, colour c,
css_border_style style, int thickness)
{
int z[8];
bool dotted = false;
unsigned int light = i;
colour c_lit;
if (c == TRANSPARENT)
return true;
switch (style) {
case CSS_BORDER_STYLE_DOTTED:
dotted = true;
case CSS_BORDER_STYLE_DASHED:
if (!plot.line((p[i * 4 + 0] + p[i * 4 + 2]) / 2,
(p[i * 4 + 1] + p[i * 4 + 3]) / 2,
(p[i * 4 + 4] + p[i * 4 + 6]) / 2,
(p[i * 4 + 5] + p[i * 4 + 7]) / 2,
thickness,
c, dotted, !dotted))
return false;
return true;
case CSS_BORDER_STYLE_SOLID:
break;
case CSS_BORDER_STYLE_DOUBLE:
z[0] = p[i * 4 + 0];
z[1] = p[i * 4 + 1];
z[2] = (p[i * 4 + 0] * 2 + p[i * 4 + 2]) / 3;
z[3] = (p[i * 4 + 1] * 2 + p[i * 4 + 3]) / 3;
z[4] = (p[i * 4 + 6] * 2 + p[i * 4 + 4]) / 3;
z[5] = (p[i * 4 + 7] * 2 + p[i * 4 + 5]) / 3;
z[6] = p[i * 4 + 6];
z[7] = p[i * 4 + 7];
if (!plot.polygon(z, 4, c))
return false;
z[0] = p[i * 4 + 2];
z[1] = p[i * 4 + 3];
z[2] = (p[i * 4 + 2] * 2 + p[i * 4 + 0]) / 3;
z[3] = (p[i * 4 + 3] * 2 + p[i * 4 + 1]) / 3;
z[4] = (p[i * 4 + 4] * 2 + p[i * 4 + 6]) / 3;
z[5] = (p[i * 4 + 5] * 2 + p[i * 4 + 7]) / 3;
z[6] = p[i * 4 + 4];
z[7] = p[i * 4 + 5];
if (!plot.polygon(z, 4, c))
return false;
return true;
case CSS_BORDER_STYLE_GROOVE:
light = 3 - light;
case CSS_BORDER_STYLE_RIDGE:
z[0] = p[i * 4 + 0];
z[1] = p[i * 4 + 1];
z[2] = (p[i * 4 + 0] + p[i * 4 + 2]) / 2;
z[3] = (p[i * 4 + 1] + p[i * 4 + 3]) / 2;
z[4] = (p[i * 4 + 6] + p[i * 4 + 4]) / 2;
z[5] = (p[i * 4 + 7] + p[i * 4 + 5]) / 2;
z[6] = p[i * 4 + 6];
z[7] = p[i * 4 + 7];
if (!plot.polygon(z, 4, light <= 1 ?
html_redraw_darker(c) :
html_redraw_lighter(c)))
return false;
z[0] = p[i * 4 + 2];
z[1] = p[i * 4 + 3];
z[6] = p[i * 4 + 4];
z[7] = p[i * 4 + 5];
if (!plot.polygon(z, 4, light <= 1 ?
html_redraw_lighter(c) :
html_redraw_darker(c)))
return false;
return true;
case CSS_BORDER_STYLE_INSET:
light = (light + 2) % 4;
case CSS_BORDER_STYLE_OUTSET:
z[0] = p[i * 4 + 0];
z[1] = p[i * 4 + 1];
z[2] = (p[i * 4 + 0] + p[i * 4 + 2]) / 2;
z[3] = (p[i * 4 + 1] + p[i * 4 + 3]) / 2;
z[4] = (p[i * 4 + 6] + p[i * 4 + 4]) / 2;
z[5] = (p[i * 4 + 7] + p[i * 4 + 5]) / 2;
z[6] = p[i * 4 + 6];
z[7] = p[i * 4 + 7];
c_lit = c;
switch (light) {
case 3:
c_lit = html_redraw_lighter(c_lit);
case 0:
c_lit = html_redraw_lighter(c_lit);
break;
case 1:
c_lit = html_redraw_darker(c_lit);
case 2:
c_lit = html_redraw_darker(c_lit);
}
if (!plot.polygon(z, 4, c_lit))
return false;
z[0] = p[i * 4 + 2];
z[1] = p[i * 4 + 3];
z[6] = p[i * 4 + 4];
z[7] = p[i * 4 + 5];
switch (light) {
case 0:
c = html_redraw_lighter(c);
case 3:
c = html_redraw_lighter(c);
break;
case 2:
c = html_redraw_darker(c);
case 1:
c = html_redraw_darker(c);
}
if (!plot.polygon(z, 4, c))
return false;
return true;
default:
break;
}
if (!plot.polygon(p + i * 4, 4, c))
return false;
return true;
}
/**
* Make a colour darker.
*
* \param c colour
* \return a darker shade of c
*/
#define mix_colour(c0, c1) ((((c0 >> 16) + 3 * (c1 >> 16)) >> 2) << 16) | \
(((((c0 >> 8) & 0xff) + 3 * ((c1 >> 8) & 0xff)) >> 2) << 8) | \
((((c0 & 0xff) + 3 * (c1 & 0xff)) >> 2) << 0);
colour html_redraw_darker(colour c)
{
return mix_colour(0x000000, c)
}
/**
* Make a colour lighter.
*
* \param c colour
* \return a lighter shade of c
*/
colour html_redraw_lighter(colour c)
{
return mix_colour(0xffffff, c)
}
/**
* Mix two colours to produce a colour suitable for anti-aliasing.
*
* \param c0 first colour
* \param c1 second colour
* \return a colour half way between c0 and c1
*/
colour html_redraw_aa(colour c0, colour c1)
{
return ((((c0 >> 16) + (c1 >> 16)) / 2) << 16) |
(((((c0 >> 8) & 0xff) + ((c1 >> 8) & 0xff)) / 2) << 8) |
((((c0 & 0xff) + (c1 & 0xff)) / 2) << 0);
}
/**
* Plot a checkbox.
*
* \param x left coordinate
* \param y top coordinate
* \param width dimensions of checkbox
* \param height dimensions of checkbox
* \param selected the checkbox is selected
* \return true if successful, false otherwise
*/
#define WIDGET_BASEC 0xd9d9d9
#define WIDGET_BLOBC 0x000000
bool html_redraw_checkbox(int x, int y, int width, int height,
bool selected)
{
int dark = html_redraw_darker(html_redraw_darker(WIDGET_BASEC));
int lite = html_redraw_lighter(html_redraw_lighter(WIDGET_BASEC));
double z = width * 0.15;
if (z == 0)
z = 1;
if (!(plot.fill(x, y, x + width, y + height, WIDGET_BASEC) &&
plot.line(x, y, x + width, y, 1, dark, false, false) &&
plot.line(x, y, x, y + height, 1, dark, false, false) &&
plot.line(x + width, y, x + width, y + height, 1, lite,
false, false) &&
plot.line(x, y + height, x + width, y + height, 1, lite,
false, false)))
return false;
if (selected) {
if (width < 12 || height < 12) {
/* render a solid box instead of a tick */
if (!plot.fill(x + z + z, y + z + z,
x + width - z, y + height - z,
WIDGET_BLOBC))
return false;
} else {
/* render a tick, as it'll fit comfortably */
if (!(plot.line(x + width - z,
y + z,
x + (z * 3),
y + height - z,
2, WIDGET_BLOBC, false, false) &&
plot.line(x + (z * 3),
y + height - z,
x + z + z,
y + (height / 2),
2, WIDGET_BLOBC, false, false)))
return false;
}
}
return true;
}
/**
* Plot a radio icon.
*
* \param x left coordinate
* \param y top coordinate
* \param width dimensions of radio icon
* \param height dimensions of radio icon
* \param selected the radio icon is selected
* \return true if successful, false otherwise
*/
bool html_redraw_radio(int x, int y, int width, int height,
bool selected)
{
int dark = html_redraw_darker(html_redraw_darker(WIDGET_BASEC));
int lite = html_redraw_lighter(html_redraw_lighter(WIDGET_BASEC));
/* plot background of radio button */
if (!plot.disc(x + width * 0.5, y + height * 0.5,
width * 0.5 - 1, WIDGET_BASEC, true))
return false;
/* plot dark arc */
if (!plot.arc(x + width * 0.5, y + height * 0.5,
width * 0.5 - 1, 45, 225, dark))
return false;
/* plot light arc */
if (!plot.arc(x + width * 0.5, y + height * 0.5,
width * 0.5 - 1, 225, 45, lite))
return false;
if (selected) {
/* plot selection blob */
if (!plot.disc(x + width * 0.5, y + height * 0.5,
width * 0.3 - 1, WIDGET_BLOBC, true))
return false;
}
return true;
}
/**
* Plot a file upload input.
*
* \param x left coordinate
* \param y top coordinate
* \param width dimensions of input
* \param height dimensions of input
* \param box box of input
* \param scale scale for redraw
* \param background_colour current background colour
* \return true if successful, false otherwise
*/
bool html_redraw_file(int x, int y, int width, int height,
struct box *box, float scale, colour background_colour)
{
int text_width;
const char *text;
size_t length;
if (box->gadget->value)
text = box->gadget->value;
else
text = messages_get("Form_Drop");
length = strlen(text);
if (!nsfont_width(box->style, text, length, &text_width))
return false;
text_width *= scale;
if (width < text_width + 8)
x = x + width - text_width - 4;
else
x = x + 4;
return plot.text(x, y + height * 0.75, box->style, text, length,
background_colour,
/*print_text_black ? 0 :*/ box->style->color);
}
/**
* Plot background images.
*
* \param x coordinate of box
* \param y coordinate of box
* \param box box to draw background image of
* \param scale scale for redraw
* \param background_colour current background colour
* \param background box containing background details (usually ::box)
* \return true if successful, false otherwise
*
* The reason for the presence of ::background is the backwards compatibility
* mess that is backgrounds on <body>. The background will be drawn relative
* to ::box, using the background information contained within ::background.
*/
bool html_redraw_background(int x, int y, struct box *box, float scale,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
colour *background_colour, struct box *background)
{
bool repeat_x = false;
bool repeat_y = false;
bool plot_colour = true;
bool plot_content;
bool clip_to_children = false;
struct box *clip_box = box;
int px0 = clip_x0, py0 = clip_y0, px1 = clip_x1, py1 = clip_y1;
int ox = x, oy = y;
struct box *parent;
plot_content = (background->background != NULL);
if (plot_content) {
/* handle background-repeat */
switch (background->style->background_repeat) {
case CSS_BACKGROUND_REPEAT_REPEAT:
repeat_x = repeat_y = true;
/* optimisation: only plot the colour if
* bitmap is not opaque */
if (background->background->bitmap)
plot_colour = !bitmap_get_opaque(
background->background->bitmap);
break;
case CSS_BACKGROUND_REPEAT_REPEAT_X:
repeat_x = true;
break;
case CSS_BACKGROUND_REPEAT_REPEAT_Y:
repeat_y = true;
break;
case CSS_BACKGROUND_REPEAT_NO_REPEAT:
break;
default:
break;
}
/* handle background-position */
switch (background->style->background_position.horz.pos) {
case CSS_BACKGROUND_POSITION_PERCENT:
x += (box->padding[LEFT] + box->width +
box->padding[RIGHT] -
background->background->width) * scale *
background->style->background_position.
horz.value.percent / 100;
break;
case CSS_BACKGROUND_POSITION_LENGTH:
x += (int) (css_len2px(&background->style->
background_position.horz.value.length,
background->style) * scale);
break;
default:
break;
}
switch (background->style->background_position.vert.pos) {
case CSS_BACKGROUND_POSITION_PERCENT:
y += (box->padding[TOP] + box->height +
box->padding[BOTTOM] -
background->background->height) * scale *
background->style->background_position.
vert.value.percent / 100;
break;
case CSS_BACKGROUND_POSITION_LENGTH:
y += (int) (css_len2px(&background->style->
background_position.vert.value.length,
background->style) * scale);
break;
default:
break;
}
}
/* special case for table rows as their background needs
* to be clipped to all the cells */
if (box->type == BOX_TABLE_ROW) {
for (parent = box->parent;
((parent) && (parent->type != BOX_TABLE));
parent = parent->parent);
assert(parent && (parent->style));
clip_to_children =
(parent->style->border_spacing.horz.value > 0) ||
(parent->style->border_spacing.vert.value > 0);
if (clip_to_children)
clip_box = box->children;
}
for (; clip_box; clip_box = clip_box->next) {
/* clip to child boxes if needed */
if (clip_to_children) {
assert(clip_box->type == BOX_TABLE_CELL);
/* update clip_* to the child cell */
clip_x0 = ox + (clip_box->x * scale);
clip_y0 = oy + (clip_box->y * scale);
clip_x1 = clip_x0 + (clip_box->padding[LEFT] +
clip_box->width +
clip_box->padding[RIGHT]) * scale;
clip_y1 = clip_y0 + (clip_box->padding[TOP] +
clip_box->height +
clip_box->padding[BOTTOM]) * scale;
if (clip_x0 < px0) clip_x0 = px0;
if (clip_y0 < py0) clip_y0 = py0;
if (clip_x1 > px1) clip_x1 = px1;
if (clip_y1 > py1) clip_y1 = py1;
/* <td> attributes override <tr> */
if ((clip_x0 >= clip_x1) || (clip_y0 >= clip_y1) ||
(clip_box->style->background_color !=
TRANSPARENT) ||
(clip_box->background &&
clip_box->background->bitmap &&
bitmap_get_opaque(
clip_box->background->bitmap)))
continue;
}
/* plot the background colour */
if (background->style->background_color != TRANSPARENT) {
*background_colour =
background->style->background_color;
if (plot_colour)
if (!plot.fill(clip_x0, clip_y0,
clip_x1, clip_y1, *background_colour))
return false;
}
/* and plot the image */
if (plot_content) {
if (!repeat_x) {
if (clip_x0 < x)
clip_x0 = x;
if (clip_x1 > x +
background->background->width *
scale)
clip_x1 = x + background->background->
width * scale;
} else if (!repeat_y) {
if (clip_y0 < y)
clip_y0 = y;
if (clip_y1 > y +
background->background->height *
scale)
clip_y1 = y + background->background->
height * scale;
}
/* valid clipping rectangles only */
if ((clip_x0 < clip_x1) && (clip_y0 < clip_y1)) {
if (!plot.clip(clip_x0, clip_y0,
clip_x1, clip_y1))
return false;
if (!content_redraw_tiled(background->
background, x, y,
ceilf(background->background->
width * scale),
ceilf(background->background->
height * scale),
clip_x0, clip_y0,
clip_x1, clip_y1,
scale, *background_colour,
repeat_x, repeat_y))
return false;
}
}
/* only <tr> rows being clipped to child boxes loop */
if (!clip_to_children)
return true;
}
return true;
}
/**
* Plot text decoration for a box.
*
* \param box box to plot decorations for
* \param x_parent x coordinate of parent of box
* \param y_parent y coordinate of parent of box
* \param scale scale for redraw
* \param background_colour current background colour
* \return true if successful, false otherwise
*/
bool html_redraw_text_decoration(struct box *box,
int x_parent, int y_parent, float scale,
colour background_colour)
{
static const css_text_decoration decoration[] = {
CSS_TEXT_DECORATION_UNDERLINE, CSS_TEXT_DECORATION_OVERLINE,
CSS_TEXT_DECORATION_LINE_THROUGH };
static const float line_ratio[] = { 0.9, 0.1, 0.5 };
int colour;
unsigned int i;
/* antialias colour for under/overline */
colour = html_redraw_aa(background_colour, box->style->color);
if (box->type == BOX_INLINE) {
if (!box->inline_end)
return true;
for (i = 0; i != NOF_ELEMENTS(decoration); i++)
if (box->style->text_decoration & decoration[i])
if (!html_redraw_text_decoration_inline(box,
x_parent, y_parent, scale,
colour, line_ratio[i]))
return false;
} else {
for (i = 0; i != NOF_ELEMENTS(decoration); i++)
if (box->style->text_decoration & decoration[i])
if (!html_redraw_text_decoration_block(box,
x_parent + box->x,
y_parent + box->y,
scale,
colour, line_ratio[i]))
return false;
}
return true;
}
/**
* Plot text decoration for an inline box.
*
* \param box box to plot decorations for, of type BOX_INLINE
* \param x x coordinate of parent of box
* \param y y coordinate of parent of box
* \param scale scale for redraw
* \param colour colour for decorations
* \param ratio position of line as a ratio of line height
* \return true if successful, false otherwise
*/
bool html_redraw_text_decoration_inline(struct box *box, int x, int y,
float scale, colour colour, float ratio)
{
for (struct box *c = box->next;
c && c != box->inline_end;
c = c->next) {
if (!plot.line((x + c->x) * scale,
(y + c->y + c->height * ratio) * scale,
(x + c->x + c->width) * scale,
(y + c->y + c->height * ratio) * scale,
0, colour, false, false))
return false;
}
return true;
}
/**
* Plot text decoration for an non-inline box.
*
* \param box box to plot decorations for, of type other than BOX_INLINE
* \param x x coordinate of box
* \param y y coordinate of box
* \param scale scale for redraw
* \param colour colour for decorations
* \param ratio position of line as a ratio of line height
* \return true if successful, false otherwise
*/
bool html_redraw_text_decoration_block(struct box *box, int x, int y,
float scale, colour colour, float ratio)
{
/* draw through text descendants */
for (struct box *c = box->children; c; c = c->next) {
if (c->type == BOX_TEXT) {
if (!plot.line((x + c->x) * scale,
(y + c->y + c->height * ratio) * scale,
(x + c->x + c->width) * scale,
(y + c->y + c->height * ratio) * scale,
0, colour, false, false))
return false;
} else if (c->type == BOX_INLINE_CONTAINER ||
c->type == BOX_BLOCK) {
if (!html_redraw_text_decoration_block(c,
x + c->x, y + c->y,
scale, colour, ratio))
return false;
}
}
return true;
}
/**
* Plot scrollbars for a scrolling box.
*
* \param box scrolling box
* \param scale scale for redraw
* \param x coordinate of box
* \param y coordinate of box
* \param padding_width width of padding box
* \param padding_height height of padding box
* \return true if successful, false otherwise
*/
bool html_redraw_scrollbars(struct box *box, float scale,
int x, int y, int padding_width, int padding_height,
colour background_colour)
{
const int w = SCROLLBAR_WIDTH * scale;
bool vscroll, hscroll;
int well_height, bar_top, bar_height;
int well_width, bar_left, bar_width;
colour vcolour = box->style->border[RIGHT].color;
colour hcolour = box->style->border[BOTTOM].color;
/** \todo We probably want to clamp to either end of the spectrum,
* rather than simply taking the inverse colour. */
if (vcolour == TRANSPARENT || vcolour == background_colour)
vcolour = background_colour ^ 0xffffff;
if (hcolour == TRANSPARENT || hcolour == background_colour)
hcolour = background_colour ^ 0xffffff;
box_scrollbar_dimensions(box, padding_width, padding_height, w,
&vscroll, &hscroll,
&well_height, &bar_top, &bar_height,
&well_width, &bar_left, &bar_width);
#define TRIANGLE(x0, y0, x1, y1, x2, y2, c) \
if (!plot.line(x0, y0, x1, y1, scale, c, false, false)) \
return false; \
if (!plot.line(x0, y0, x2, y2, scale, c, false, false)) \
return false; \
if (!plot.line(x1, y1, x2, y2, scale, c, false, false)) \
return false;
/* fill scrollbar well(s) with background colour */
if (vscroll)
if (!plot.fill(x + padding_width - w, y,
x + padding_width, y + padding_height,
background_colour))
return false;
if (hscroll)
if (!plot.fill(x, y + padding_height - w,
x + padding_width, y + padding_height,
background_colour))
return false;
/* vertical scrollbar */
if (vscroll) {
/* left line */
if (!plot.line(x + padding_width - w, y,
x + padding_width - w, y + padding_height,
scale, vcolour, false, false))
return false;
/* up arrow */
TRIANGLE(x + padding_width - w / 2, y + w / 4,
x + padding_width - w * 3 / 4, y + w * 3 / 4,
x + padding_width - w / 4, y + w * 3 / 4,
vcolour);
/* separator */
if (!plot.line(x + padding_width - w, y + w,
x + padding_width, y + w,
scale, vcolour, false, false))
return false;
/* bar */
if (!plot.rectangle(x + padding_width - w * 3 / 4,
y + w + bar_top + w / 4,
w / 2, bar_height - w / 2,
scale, vcolour, false, false))
return false;
/* separator */
if (!plot.line(x + padding_width - w, y + w + well_height,
x + padding_width, y + w + well_height,
scale, vcolour, false, false))
return false;
/* down arrow */
TRIANGLE(x + padding_width - w / 2,
y + w + well_height + w * 3 / 4,
x + padding_width - w * 3 / 4,
y + w + well_height + w / 4,
x + padding_width - w / 4,
y + w + well_height + w / 4,
vcolour);
}
/* horizontal scrollbar */
if (hscroll) {
/* top line */
if (!plot.line(x, y + padding_height - w,
x + well_width + w + w, y + padding_height - w,
scale, hcolour, false, false))
return false;
/* left arrow */
TRIANGLE(x + w / 4, y + padding_height - w / 2,
x + w * 3 / 4, y + padding_height - w * 3 / 4,
x + w * 3 / 4, y + padding_height - w / 4,
hcolour);
/* separator */
if (!plot.line(x + w, y + padding_height - w,
x + w, y + padding_height,
scale, hcolour, false, false))
return false;
/* bar */
if (!plot.rectangle(x + w + bar_left + w / 4,
y + padding_height - w * 3 / 4,
bar_width - w / 2, w / 2,
scale, hcolour, false, false))
return false;
/* separator */
if (!plot.line(x + w + well_width, y + padding_height - w,
x + w + well_width, y + padding_height,
scale, hcolour, false, false))
return false;
/* right arrow */
TRIANGLE(x + w + well_width + w * 3 / 4,
y + padding_height - w / 2,
x + w + well_width + w / 4,
y + padding_height - w * 3 / 4,
x + w + well_width + w / 4,
y + padding_height - w / 4,
hcolour);
}
return true;
}
/**
* Determine if a box has a vertical scrollbar.
*
* \param box scrolling box
* \return the box has a vertical scrollbar
*/
bool box_vscrollbar_present(const struct box * const box)
{
return box->descendant_y0 < -box->border[TOP] ||
box->padding[TOP] + box->height + box->padding[BOTTOM] +
box->border[BOTTOM] < box->descendant_y1;
}
/**
* Determine if a box has a horizontal scrollbar.
*
* \param box scrolling box
* \return the box has a horizontal scrollbar
*/
bool box_hscrollbar_present(const struct box * const box)
{
return box->descendant_x0 < -box->border[LEFT] ||
box->padding[LEFT] + box->width + box->padding[RIGHT] +
box->border[RIGHT] < box->descendant_x1;
}
/**
* Calculate scrollbar dimensions and positions for a box.
*
* \param box scrolling box
* \param padding_width scaled width of padding box
* \param padding_height scaled height of padding box
* \param w scaled scrollbar width
* \param vscroll updated to vertical scrollbar present
* \param hscroll updated to horizontal scrollbar present
* \param well_height updated to vertical well height
* \param bar_top updated to top position of vertical scrollbar
* \param bar_height updated to height of vertical scrollbar
* \param well_width updated to horizontal well width
* \param bar_left updated to left position of horizontal scrollbar
* \param bar_width updated to width of horizontal scrollbar
*/
void box_scrollbar_dimensions(const struct box * const box,
const int padding_width, const int padding_height, const int w,
bool * const vscroll, bool * const hscroll,
int * const well_height,
int * const bar_top, int * const bar_height,
int * const well_width,
int * const bar_left, int * const bar_width)
{
*vscroll = box_vscrollbar_present(box);
*hscroll = box_hscrollbar_present(box);
*well_height = padding_height - w - w;
*bar_top = 0;
*bar_height = *well_height;
if (box->descendant_y1 - box->descendant_y0 != 0) {
*bar_top = (float) *well_height * (float) box->scroll_y /
(float) (box->descendant_y1 -
box->descendant_y0);
*bar_height = (float) *well_height * (float) box->height /
(float) (box->descendant_y1 -
box->descendant_y0);
}
*well_width = padding_width - w - w - (*vscroll ? w : 0);
*bar_left = 0;
*bar_width = *well_width;
if (box->descendant_x1 - box->descendant_x0 != 0) {
*bar_left = (float) *well_width * (float) box->scroll_x /
(float) (box->descendant_x1 -
box->descendant_x0);
*bar_width = (float) *well_width * (float) box->width /
(float) (box->descendant_x1 -
box->descendant_x0);
}
}