gtk2/gtk/gtktextutil.c
2016-04-26 21:25:02 -04:00

509 lines
15 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Modified by the GTK+ Team and others 1997-2001. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
#include "gtktextview.h"
#include "gtktextutil.h"
#define GTK_TEXT_USE_INTERNAL_UNSUPPORTED_API
#include "gtktextdisplay.h"
#include "gtktextbuffer.h"
#include "gtkmenuitem.h"
#include "gtkintl.h"
#define DRAG_ICON_MAX_WIDTH 250
#define DRAG_ICON_MAX_HEIGHT 250
#define DRAG_ICON_MAX_LINES 7
#define ELLIPSIS_CHARACTER "\xe2\x80\xa6"
typedef struct _GtkUnicodeMenuEntry GtkUnicodeMenuEntry;
typedef struct _GtkTextUtilCallbackInfo GtkTextUtilCallbackInfo;
struct _GtkUnicodeMenuEntry {
const char *label;
gunichar ch;
};
struct _GtkTextUtilCallbackInfo
{
GtkTextUtilCharChosenFunc func;
gpointer data;
};
static const GtkUnicodeMenuEntry bidi_menu_entries[] = {
{ N_("LRM _Left-to-right mark"), 0x200E },
{ N_("RLM _Right-to-left mark"), 0x200F },
{ N_("LRE Left-to-right _embedding"), 0x202A },
{ N_("RLE Right-to-left e_mbedding"), 0x202B },
{ N_("LRO Left-to-right _override"), 0x202D },
{ N_("RLO Right-to-left o_verride"), 0x202E },
{ N_("PDF _Pop directional formatting"), 0x202C },
{ N_("ZWS _Zero width space"), 0x200B },
{ N_("ZWJ Zero width _joiner"), 0x200D },
{ N_("ZWNJ Zero width _non-joiner"), 0x200C }
};
static GtkTextUtilCallbackInfo *
callback_info_new (GtkTextUtilCharChosenFunc func,
gpointer data)
{
GtkTextUtilCallbackInfo *info;
info = g_slice_new (GtkTextUtilCallbackInfo);
info->func = func;
info->data = data;
return info;
}
static void
callback_info_free (GtkTextUtilCallbackInfo *info)
{
g_slice_free (GtkTextUtilCallbackInfo, info);
}
static void
activate_cb (GtkWidget *menu_item,
gpointer data)
{
GtkUnicodeMenuEntry *entry;
GtkTextUtilCallbackInfo *info = data;
char buf[7];
entry = g_object_get_data (G_OBJECT (menu_item), "gtk-unicode-menu-entry");
buf[g_unichar_to_utf8 (entry->ch, buf)] = '\0';
(* info->func) (buf, info->data);
}
/*
* _gtk_text_util_append_special_char_menuitems
* @menushell: a #GtkMenuShell
* @callback: call this when an item is chosen
* @data: data for callback
*
* Add menuitems for various bidi control characters to a menu;
* the menuitems, when selected, will call the given function
* with the chosen character.
*
* This function is private/internal in GTK 2.0, the functionality may
* become public sometime, but it probably needs more thought first.
* e.g. maybe there should be a way to just get the list of items,
* instead of requiring the menu items to be created.
*/
void
_gtk_text_util_append_special_char_menuitems (GtkMenuShell *menushell,
GtkTextUtilCharChosenFunc func,
gpointer data)
{
int i;
for (i = 0; i < G_N_ELEMENTS (bidi_menu_entries); i++)
{
GtkWidget *menuitem;
GtkTextUtilCallbackInfo *info;
info = callback_info_new (func, data);
menuitem = gtk_menu_item_new_with_mnemonic (_(bidi_menu_entries[i].label));
g_object_set_data (G_OBJECT (menuitem), I_("gtk-unicode-menu-entry"),
(gpointer)&bidi_menu_entries[i]);
g_signal_connect_data (menuitem, "activate",
G_CALLBACK (activate_cb),
info, (GClosureNotify) callback_info_free, 0);
gtk_widget_show (menuitem);
gtk_menu_shell_append (menushell, menuitem);
}
}
static void
append_n_lines (GString *str, const gchar *text, GSList *lines, gint n_lines)
{
PangoLayoutLine *line;
gint i;
for (i = 0; i < n_lines; i++)
{
line = lines->data;
g_string_append_len (str, &text[line->start_index], line->length);
lines = lines->next;
}
}
static void
limit_layout_lines (PangoLayout *layout)
{
const gchar *text;
GString *str;
GSList *lines, *elem;
gint n_lines;
n_lines = pango_layout_get_line_count (layout);
if (n_lines >= DRAG_ICON_MAX_LINES)
{
text = pango_layout_get_text (layout);
str = g_string_new (NULL);
lines = pango_layout_get_lines_readonly (layout);
/* get first lines */
elem = lines;
append_n_lines (str, text, elem,
DRAG_ICON_MAX_LINES / 2);
g_string_append (str, "\n" ELLIPSIS_CHARACTER "\n");
/* get last lines */
elem = g_slist_nth (lines, n_lines - DRAG_ICON_MAX_LINES / 2);
append_n_lines (str, text, elem,
DRAG_ICON_MAX_LINES / 2);
pango_layout_set_text (layout, str->str, -1);
g_string_free (str, TRUE);
}
}
/**
* _gtk_text_util_create_drag_icon:
* @widget: #GtkWidget to extract the pango context
* @text: a #gchar to render the icon
* @len: length of @text, or -1 for NUL-terminated text
*
* Creates a drag and drop icon from @text.
*
* Returns: a #cairo_surface_t to use as DND icon
*/
cairo_surface_t *
_gtk_text_util_create_drag_icon (GtkWidget *widget,
gchar *text,
gsize len)
{
GtkStyleContext *style_context;
cairo_surface_t *surface;
PangoContext *context;
PangoLayout *layout;
cairo_t *cr;
gint pixmap_height, pixmap_width;
gint layout_width, layout_height;
GdkRGBA color;
g_return_val_if_fail (widget != NULL, NULL);
g_return_val_if_fail (text != NULL, NULL);
context = gtk_widget_get_pango_context (widget);
layout = pango_layout_new (context);
pango_layout_set_text (layout, text, len);
pango_layout_set_wrap (layout, PANGO_WRAP_WORD_CHAR);
pango_layout_get_size (layout, &layout_width, &layout_height);
layout_width = MIN (layout_width, DRAG_ICON_MAX_WIDTH * PANGO_SCALE);
pango_layout_set_width (layout, layout_width);
limit_layout_lines (layout);
/* get again layout extents, they may have changed */
pango_layout_get_size (layout, &layout_width, &layout_height);
pixmap_width = layout_width / PANGO_SCALE;
pixmap_height = layout_height / PANGO_SCALE;
surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
CAIRO_CONTENT_COLOR_ALPHA,
pixmap_width, pixmap_height);
cr = cairo_create (surface);
style_context = gtk_widget_get_style_context (widget);
gtk_style_context_get_color (style_context,
gtk_style_context_get_state (style_context),
&color);
gdk_cairo_set_source_rgba (cr, &color);
pango_cairo_show_layout (cr, layout);
cairo_destroy (cr);
g_object_unref (layout);
return surface;
}
static void
set_attributes_from_style (GtkStyleContext *context,
GtkTextAttributes *values)
{
GdkRGBA bg_color, fg_color;
GtkStateFlags state;
state = gtk_style_context_get_state (context);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
gtk_style_context_get_background_color (context, state, &bg_color);
G_GNUC_END_IGNORE_DEPRECATIONS
gtk_style_context_get_color (context, state, &fg_color);
values->appearance.bg_color.red = CLAMP (bg_color.red * 65535. + 0.5, 0, 65535);
values->appearance.bg_color.green = CLAMP (bg_color.green * 65535. + 0.5, 0, 65535);
values->appearance.bg_color.blue = CLAMP (bg_color.blue * 65535. + 0.5, 0, 65535);
values->appearance.fg_color.red = CLAMP (fg_color.red * 65535. + 0.5, 0, 65535);
values->appearance.fg_color.green = CLAMP (fg_color.green * 65535. + 0.5, 0, 65535);
values->appearance.fg_color.blue = CLAMP (fg_color.blue * 65535. + 0.5, 0, 65535);
if (values->font)
pango_font_description_free (values->font);
gtk_style_context_get (context, state, "font", &values->font, NULL);
}
cairo_surface_t *
_gtk_text_util_create_rich_drag_icon (GtkWidget *widget,
GtkTextBuffer *buffer,
GtkTextIter *start,
GtkTextIter *end)
{
GtkAllocation allocation;
cairo_surface_t *surface;
gint layout_width, layout_height;
GtkTextBuffer *new_buffer;
GtkTextLayout *layout;
GtkTextAttributes *style;
PangoContext *ltr_context, *rtl_context;
GtkTextIter iter;
cairo_t *cr;
g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
g_return_val_if_fail (GTK_IS_TEXT_BUFFER (buffer), NULL);
g_return_val_if_fail (start != NULL, NULL);
g_return_val_if_fail (end != NULL, NULL);
new_buffer = gtk_text_buffer_new (gtk_text_buffer_get_tag_table (buffer));
gtk_text_buffer_get_start_iter (new_buffer, &iter);
gtk_text_buffer_insert_range (new_buffer, &iter, start, end);
gtk_text_buffer_get_start_iter (new_buffer, &iter);
layout = gtk_text_layout_new ();
ltr_context = gtk_widget_create_pango_context (widget);
pango_context_set_base_dir (ltr_context, PANGO_DIRECTION_LTR);
rtl_context = gtk_widget_create_pango_context (widget);
pango_context_set_base_dir (rtl_context, PANGO_DIRECTION_RTL);
gtk_text_layout_set_contexts (layout, ltr_context, rtl_context);
g_object_unref (ltr_context);
g_object_unref (rtl_context);
style = gtk_text_attributes_new ();
gtk_widget_get_allocation (widget, &allocation);
layout_width = allocation.width;
set_attributes_from_style (gtk_widget_get_style_context (widget), style);
if (GTK_IS_TEXT_VIEW (widget))
{
layout_width = layout_width
- gtk_text_view_get_border_window_size (GTK_TEXT_VIEW (widget), GTK_TEXT_WINDOW_LEFT)
- gtk_text_view_get_border_window_size (GTK_TEXT_VIEW (widget), GTK_TEXT_WINDOW_RIGHT);
}
style->direction = gtk_widget_get_direction (widget);
style->wrap_mode = GTK_WRAP_WORD_CHAR;
gtk_text_layout_set_default_style (layout, style);
gtk_text_attributes_unref (style);
gtk_text_layout_set_buffer (layout, new_buffer);
gtk_text_layout_set_cursor_visible (layout, FALSE);
gtk_text_layout_set_screen_width (layout, layout_width);
gtk_text_layout_validate (layout, DRAG_ICON_MAX_HEIGHT);
gtk_text_layout_get_size (layout, &layout_width, &layout_height);
layout_width = MIN (layout_width, DRAG_ICON_MAX_WIDTH);
layout_height = MIN (layout_height, DRAG_ICON_MAX_HEIGHT);
surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
CAIRO_CONTENT_COLOR_ALPHA,
layout_width, layout_height);
cr = cairo_create (surface);
gtk_text_layout_draw (layout, widget, cr, NULL);
cairo_destroy (cr);
g_object_unref (layout);
g_object_unref (new_buffer);
return surface;
}
static gint
layout_get_char_width (PangoLayout *layout)
{
gint width;
PangoFontMetrics *metrics;
const PangoFontDescription *font_desc;
PangoContext *context = pango_layout_get_context (layout);
font_desc = pango_layout_get_font_description (layout);
if (!font_desc)
font_desc = pango_context_get_font_description (context);
metrics = pango_context_get_metrics (context, font_desc, NULL);
width = pango_font_metrics_get_approximate_char_width (metrics);
pango_font_metrics_unref (metrics);
return width;
}
/*
* _gtk_text_util_get_block_cursor_location
* @layout: a #PangoLayout
* @index: index at which cursor is located
* @pos: cursor location
* @at_line_end: whether cursor is drawn at line end, not over some
* character
*
* Returns: whether cursor should actually be drawn as a rectangle.
* It may not be the case if character at index is invisible.
*/
gboolean
_gtk_text_util_get_block_cursor_location (PangoLayout *layout,
gint index,
PangoRectangle *pos,
gboolean *at_line_end)
{
PangoRectangle strong_pos, weak_pos;
PangoLayoutLine *layout_line;
gboolean rtl;
gint line_no;
const gchar *text;
g_return_val_if_fail (layout != NULL, FALSE);
g_return_val_if_fail (index >= 0, FALSE);
g_return_val_if_fail (pos != NULL, FALSE);
pango_layout_index_to_pos (layout, index, pos);
if (pos->width != 0)
{
/* cursor is at some visible character, good */
if (at_line_end)
*at_line_end = FALSE;
if (pos->width < 0)
{
pos->x += pos->width;
pos->width = -pos->width;
}
return TRUE;
}
pango_layout_index_to_line_x (layout, index, FALSE, &line_no, NULL);
layout_line = pango_layout_get_line_readonly (layout, line_no);
g_return_val_if_fail (layout_line != NULL, FALSE);
text = pango_layout_get_text (layout);
if (index < layout_line->start_index + layout_line->length)
{
/* this may be a zero-width character in the middle of the line,
* or it could be a character where line is wrapped, we do want
* block cursor in latter case */
if (g_utf8_next_char (text + index) - text !=
layout_line->start_index + layout_line->length)
{
/* zero-width character in the middle of the line, do not
* bother with block cursor */
return FALSE;
}
}
/* Cursor is at the line end. It may be an empty line, or it could
* be on the left or on the right depending on text direction, or it
* even could be in the middle of visual layout in bidi text. */
pango_layout_get_cursor_pos (layout, index, &strong_pos, &weak_pos);
if (strong_pos.x != weak_pos.x)
{
/* do not show block cursor in this case, since the character typed
* in may or may not appear at the cursor position */
return FALSE;
}
/* In case when index points to the end of line, pos->x is always most right
* pixel of the layout line, so we need to correct it for RTL text. */
if (layout_line->length)
{
if (layout_line->resolved_dir == PANGO_DIRECTION_RTL)
{
PangoLayoutIter *iter;
PangoRectangle line_rect;
gint i;
gint left, right;
const gchar *p;
p = g_utf8_prev_char (text + index);
pango_layout_line_index_to_x (layout_line, p - text, FALSE, &left);
pango_layout_line_index_to_x (layout_line, p - text, TRUE, &right);
pos->x = MIN (left, right);
iter = pango_layout_get_iter (layout);
for (i = 0; i < line_no; i++)
pango_layout_iter_next_line (iter);
pango_layout_iter_get_line_extents (iter, NULL, &line_rect);
pango_layout_iter_free (iter);
rtl = TRUE;
pos->x += line_rect.x;
}
else
rtl = FALSE;
}
else
{
PangoContext *context = pango_layout_get_context (layout);
rtl = pango_context_get_base_dir (context) == PANGO_DIRECTION_RTL;
}
pos->width = layout_get_char_width (layout);
if (rtl)
pos->x -= pos->width - 1;
if (at_line_end)
*at_line_end = TRUE;
return pos->width != 0;
}