Commit 4ea00e10 authored by Owen W. Taylor's avatar Owen W. Taylor
Browse files

Add an "Above_Tab" pseudo-keysym

We want switching between the windows of an application to be an easily
accessible operation. The convenient and memorable keybinding is the
key above the tab key - but the keysym for that key isn't consistent
across different keyboard layouts.

Add code that figures out the key from the XKB geometry and a magic
keysym name "Above_Tab" that refers to this key and switch
the default binding for cycle_group to <Alt>Above_Tab. (This will
have no effect for the normal case of getting the key binding from
GConf until this patch is applied to Metacity as well.)

https://bugzilla.gnome.org/show_bug.cgi?id=635569
parent ed99d12e
......@@ -51,6 +51,7 @@ mutter_SOURCES= \
include/meta-shadow-factory.h \
include/meta-window-actor.h \
include/compositor-mutter.h \
core/above-tab-keycode.c \
core/constraints.c \
core/constraints.h \
core/core.c \
......
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* Find the keycode for the key above the tab key */
/*
* Copyright 2010 Red Hat, Inc.
*
* This program 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; either version 2 of the
* License, or (at your option) any later version.
*
* This program 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
/* The standard cycle-windows keybinding should be the key above the
* tab key. This will have a different keysym on different keyboards -
* it's the ` (grave) key on US keyboards but something else on many
* other national layouts. So we need to figure out the keycode for
* this key without reference to key symbol.
*
* The "correct" way to do this is to get the XKB geometry from the
* X server, find the Tab key, find the key above the Tab key in the
* same section and use the keycode for that key. This is what I
* implemented here, but unfortunately, fetching the geometry is rather
* slow (It could take 20ms or more.)
*
* If you looking for a way to optimize Mutter startup performance:
* On all Linux systems using evdev the key above TAB will have
* keycode 49. (KEY_GRAVE=41 + the 8 code point offset between
* evdev keysyms and X keysyms.) So a configure option
* --with-above-tab-keycode=49 could be added that bypassed this
* code. It wouldn't work right for displaying Mutter remotely
* to a non-Linux X server, but that is pretty rare.
*/
#include <config.h>
#include <string.h>
#include "display-private.h"
#include <X11/keysym.h>
#ifdef HAVE_XKB
#include <X11/XKBlib.h>
#include <X11/extensions/XKBgeom.h>
static guint
compute_above_tab_keycode (Display *xdisplay)
{
XkbDescPtr keyboard;
XkbGeometryPtr geometry;
int i, j, k;
int tab_keycode;
char *tab_name;
XkbSectionPtr tab_section;
XkbBoundsRec tab_bounds;
XkbKeyPtr best_key = NULL;
guint best_keycode = (guint)-1;
int best_x_dist = G_MAXINT;
int best_y_dist = G_MAXINT;
/* We need only the Names and the Geometry, but asking for these results
* in the Keyboard information retrieval failing for unknown reasons.
* (Testing with xorg-1.9.1.) So we ask for a part that we don't need
* as well.
*/
keyboard = XkbGetKeyboard (xdisplay,
XkbGBN_ClientSymbolsMask | XkbGBN_KeyNamesMask | XkbGBN_GeometryMask,
XkbUseCoreKbd);
geometry = keyboard->geom;
/* There could potentially be multiple keys with the Tab keysym on the keyboard;
* but XKeysymToKeycode() returns us the one that the alt-Tab binding will
* use which is good enough
*/
tab_keycode = XKeysymToKeycode (xdisplay, XK_Tab);
if (tab_keycode == 0 || tab_keycode < keyboard->min_key_code || tab_keycode > keyboard->max_key_code)
goto out;
/* The keyboard geometry is stored by key "name" rather than keycode.
* (Key names are 4-character strings like like TAB or AE01.) We use the
* 'names' part of the keyboard description to map keycode to key name.
*
* XKB has a "key aliases" feature where a single keyboard key can have
* multiple names (with separate sets of aliases in the 'names' part and
* in the 'geometry' part), but I don't really understand it or how it is used,
* so I'm ignoring it here.
*/
tab_name = keyboard->names->keys[tab_keycode].name; /* Not NULL terminated! */
/* First, iterate through the keyboard geometry to find the tab key; the keyboard
* geometry has a three-level heirarchy of section > row > key
*/
for (i = 0; i < geometry->num_sections; i++)
{
XkbSectionPtr section = &geometry->sections[i];
for (j = 0; j < section->num_rows; j++)
{
int x = 0;
int y = 0;
XkbRowPtr row = &section->rows[j];
for (k = 0; k < row->num_keys; k++)
{
XkbKeyPtr key = &row->keys[k];
XkbShapePtr shape = XkbKeyShape (geometry, key);
if (row->vertical)
y += key->gap;
else
x += key->gap;
if (strncmp (key->name.name, tab_name, XkbKeyNameLength) == 0)
{
tab_section = section;
tab_bounds = shape->bounds;
tab_bounds.x1 += row->left + x;
tab_bounds.x2 += row->left + x;
tab_bounds.y1 += row->top + y;
tab_bounds.y2 += row->top + y;
goto found_tab;
}
if (row->vertical)
y += (shape->bounds.y2 - shape->bounds.y1);
else
x += (shape->bounds.x2 - shape->bounds.x1);
}
}
}
/* No tab key found */
goto out;
found_tab:
/* Now find the key that:
* - Is in the same section as the Tab key
* - Has a horizontal center in the Tab key's horizonal bounds
* - Is above the Tab key at a distance closer than any other key
* - In case of ties, has its horizontal center as close as possible
* to the Tab key's horizontal center
*/
for (j = 0; j < tab_section->num_rows; j++)
{
int x = 0;
int y = 0;
XkbRowPtr row = &tab_section->rows[j];
for (k = 0; k < row->num_keys; k++)
{
XkbKeyPtr key = &row->keys[k];
XkbShapePtr shape = XkbKeyShape(geometry, key);
XkbBoundsRec bounds = shape->bounds;
int x_center;
int x_dist, y_dist;
if (row->vertical)
y += key->gap;
else
x += key->gap;
bounds.x1 += row->left + x;
bounds.x2 += row->left + x;
bounds.y1 += row->top + y;
bounds.y2 += row->top + y;
y_dist = tab_bounds.y1 - bounds.y2;
if (y_dist < 0)
continue;
x_center = (bounds.x1 + bounds.x2) / 2;
if (x_center < tab_bounds.x1 || x_center > tab_bounds.x2)
continue;
x_dist = ABS (x_center - (tab_bounds.x1 + tab_bounds.x2) / 2);
if (y_dist < best_y_dist ||
(y_dist == best_y_dist && x_dist < best_x_dist))
{
best_key = key;
best_x_dist = x_dist;
best_y_dist = y_dist;
}
if (row->vertical)
y += (shape->bounds.y2 - shape->bounds.y1);
else
x += (shape->bounds.x2 - shape->bounds.x1);
}
}
if (best_key == NULL)
goto out;
/* Now we need to resolve the name of the best key back to a keycode */
for (i = keyboard->min_key_code; i < keyboard->max_key_code; i++)
{
if (strncmp (best_key->name.name, keyboard->names->keys[i].name, XkbKeyNameLength) == 0)
{
best_keycode = i;
break;
}
}
out:
XkbFreeKeyboard (keyboard, 0, True);
return best_keycode;
}
#else /* !HAVE_XKB */
static guint
compute_above_tab_keycode (Display *xdisplay)
{
return XKeysymToKeycode (xdisplay, XK_grave);
}
#endif /* HAVE_XKB */
guint
meta_display_get_above_tab_keycode (MetaDisplay *display)
{
if (display->above_tab_keycode == 0) /* not yet computed */
display->above_tab_keycode = compute_above_tab_keycode (display->xdisplay);
if (display->above_tab_keycode == (guint)-1) /* failed to compute */
return 0;
else
return display->above_tab_keycode;
}
......@@ -221,6 +221,7 @@ struct _MetaDisplay
KeySym *keymap;
int keysyms_per_keycode;
XModifierKeymap *modmap;
unsigned int above_tab_keycode;
unsigned int ignored_modifier_mask;
unsigned int num_lock_mask;
unsigned int scroll_lock_mask;
......@@ -433,4 +434,7 @@ void meta_display_remove_autoraise_callback (MetaDisplay *display);
void meta_display_overlay_key_activate (MetaDisplay *display);
/* In above-tab-keycode.c */
guint meta_display_get_above_tab_keycode (MetaDisplay *display);
#endif
......@@ -117,6 +117,10 @@ reload_keymap (MetaDisplay *display)
if (display->keymap)
meta_XFree (display->keymap);
/* This is expensive to compute, so we'll lazily load if and when we first
* need it */
display->above_tab_keycode = 0;
display->keymap = XGetKeyboardMapping (display->xdisplay,
display->min_keycode,
display->max_keycode -
......@@ -228,6 +232,16 @@ reload_modmap (MetaDisplay *display)
display->meta_mask);
}
static guint
keysym_to_keycode (MetaDisplay *display,
guint keysym)
{
if (keysym == META_KEY_ABOVE_TAB)
return meta_display_get_above_tab_keycode (display);
else
return XKeysymToKeycode (display->xdisplay, keysym);
}
static void
reload_keycodes (MetaDisplay *display)
{
......@@ -236,8 +250,8 @@ reload_keycodes (MetaDisplay *display)
if (display->overlay_key_combo.keysym != 0)
{
display->overlay_key_combo.keycode = XKeysymToKeycode (
display->xdisplay, display->overlay_key_combo.keysym);
display->overlay_key_combo.keycode =
keysym_to_keycode (display, display->overlay_key_combo.keysym);
}
if (display->key_bindings)
......@@ -249,8 +263,8 @@ reload_keycodes (MetaDisplay *display)
{
if (display->key_bindings[i].keysym != 0)
{
display->key_bindings[i].keycode = XKeysymToKeycode (
display->xdisplay, display->key_bindings[i].keysym);
display->key_bindings[i].keycode =
keysym_to_keycode (display, display->key_bindings[i].keysym);
}
++i;
......
......@@ -167,7 +167,7 @@ keybind (switch_panels_backward, handle_switch, META_TAB_LIST_DOCKS,
"using a popup window"))
keybind (cycle_group, handle_cycle, META_TAB_LIST_GROUP,
BINDING_REVERSES, "<Alt>grave",
BINDING_REVERSES, "<Alt>Above_Tab",
_("Move between windows of an application immediately"))
keybind (cycle_group_backward, handle_cycle, META_TAB_LIST_GROUP,
REVERSES_AND_REVERSED, NULL,
......
......@@ -157,6 +157,12 @@ void meta_ui_set_current_theme (const char *name,
gboolean force_reload);
gboolean meta_ui_have_a_theme (void);
/* Not a real key symbol but means "key above the tab key"; this is
* used as the default keybinding for cycle_group.
* 0x2xxxxxxx is a range not used by GDK or X. the remaining digits are
* randomly chosen */
#define META_KEY_ABOVE_TAB 0x2f7259c9
gboolean meta_ui_parse_accelerator (const char *accel,
unsigned int *keysym,
unsigned int *keycode,
......
......@@ -761,14 +761,50 @@ meta_ui_accelerator_parse (const char *accel,
guint *keycode,
GdkModifierType *keymask)
{
const char *above_tab;
if (accel[0] == '0' && accel[1] == 'x')
{
*keysym = 0;
*keycode = (guint) strtoul (accel, NULL, 16);
*keymask = 0;
return;
}
else
gtk_accelerator_parse (accel, keysym, keymask);
/* The key name 'Above_Tab' is special - it's not an actual keysym name,
* but rather refers to the key above the tab key. In order to use
* the GDK parsing for modifiers in combination with it, we substitute
* it with 'Tab' temporarily before calling gtk_accelerator_parse().
*/
#define is_word_character(c) (g_ascii_isalnum(c) || ((c) == '_'))
#define ABOVE_TAB "Above_Tab"
#define ABOVE_TAB_LEN 9
above_tab = strstr (accel, ABOVE_TAB);
if (above_tab &&
(above_tab == accel || !is_word_character (above_tab[-1])) &&
!is_word_character (above_tab[ABOVE_TAB_LEN]))
{
char *before = g_strndup (accel, above_tab - accel);
char *after = g_strdup (above_tab + ABOVE_TAB_LEN);
char *replaced = g_strconcat (before, "Tab", after, NULL);
gtk_accelerator_parse (replaced, NULL, keymask);
g_free (before);
g_free (after);
g_free (replaced);
*keysym = META_KEY_ABOVE_TAB;
return;
}
#undef is_word_character
#undef ABOVE_TAB
#undef ABOVE_TAB_LEN
gtk_accelerator_parse (accel, keysym, keymask);
}
gboolean
......
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