mutter/src/core/stack-tracker.c
Owen W. Taylor 21f123c69f Don't restack windows while we are unmanaging them
Restacking the frame for a window while unmanaging the window is
harmless, but for undecorated (in particular, client-side-decorated)
windows, this causes problems because the window is typically
destroyed by the client immediately after withredrawing the window.

Skip windows flagged as being unmanaged when assembling the new
stack and when comparing the old order to the new stack.

Add a stacking test for this.
2014-09-16 13:44:42 -04:00

1142 lines
32 KiB
C

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/*
* SECTION:stack-tracker
* @short_description: Track stacking order for compositor
*
* #MetaStackTracker maintains the most accurate view we have at a
* given point of time of the ordering of the children of the root
* window (including override-redirect windows.) This is used to order
* the windows when the compositor draws them.
*
* By contrast, #MetaStack is responsible for keeping track of how we
* think that windows *should* be ordered. For windows we manage
* (non-override-redirect windows), the two stacking orders will be
* the same.
*/
/*
* Copyright (C) 2009 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, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <string.h>
#include "frame.h"
#include "screen-private.h"
#include "stack-tracker.h"
#include <meta/errors.h>
#include <meta/util.h>
#include <meta/compositor.h>
/* The complexity here comes from resolving two competing factors:
*
* - We need to have a view of the stacking order that takes into
* account everything we have done without waiting for events
* back from the X server; we don't want to draw intermediate
* partially-stacked stack states just because we haven't received
* some notification yet.
*
* - Only the X server has an accurate view of the complete stacking;
* when we make a request to restack windows, we don't know how
* it will affect override-redirect windows, because at any point
* applications may restack these windows without our involvement.
*
* The technique we use is that we keep three sets of information:
*
* - The stacking order on the server as known from the last
* event we received.
* - A queue of stacking requests that *we* made subsequent to
* that last event.
* - A predicted stacking order, derived from applying the queued
* requests to the last state from the server.
*
* When we receive a new event: a) we compare the serial in the event to
* the serial of the queued requests and remove any that are now
* no longer pending b) if necessary, drop the predicted stacking
* order to recompute it at the next opportunity.
*
* Possible optimizations:
* Keep the stacks as an array + reverse-mapping hash table to avoid
* linear lookups.
* Keep the stacks as a GList + reverse-mapping hash table to avoid
* linear lookups and to make restacking constant-time.
*/
typedef union _MetaStackOp MetaStackOp;
typedef enum {
STACK_OP_ADD,
STACK_OP_REMOVE,
STACK_OP_RAISE_ABOVE,
STACK_OP_LOWER_BELOW
} MetaStackOpType;
typedef enum {
APPLY_DEFAULT = 0,
/* Only do restacking that we can do locally without changing
* the order of X windows. After we've received any stack
* events from the X server, we apply the locally cached
* ops in this mode to handle the non-X parts */
NO_RESTACK_X_WINDOWS = 1 << 0,
/* If the stacking operation wouldn't change the order of X
* windows, ignore it. We use this when applying events received
* from X so that a spontaneous ConfigureNotify (for a move, say)
* doesn't change the stacking of X windows with respect to
* Wayland windows. */
IGNORE_NOOP_X_RESTACK = 1 << 1
} ApplyFlags;
/* MetaStackOp represents a "stacking operation" - a change to
* apply to a window stack. Depending on the context, it could
* either reflect a request we have sent to the server, or a
* notification event we received from the X server.
*/
union _MetaStackOp
{
struct {
MetaStackOpType type;
gulong serial;
guint64 window;
} any;
struct {
MetaStackOpType type;
gulong serial;
guint64 window;
} add;
struct {
MetaStackOpType type;
gulong serial;
guint64 window;
} remove;
struct {
MetaStackOpType type;
gulong serial;
guint64 window;
guint64 sibling;
} raise_above;
struct {
MetaStackOpType type;
gulong serial;
guint64 window;
guint64 sibling;
} lower_below;
};
struct _MetaStackTracker
{
MetaScreen *screen;
/* This is the serial of the last request we made that was reflected
* in xserver_stack
*/
gulong xserver_serial;
/* A combined stack containing X and Wayland windows but without
* any unverified operations applied. */
GArray *verified_stack;
/* This is a queue of requests we've made to change the stacking order,
* where we haven't yet gotten a reply back from the server.
*/
GQueue *unverified_predictions;
/* This is how we think the stack is, based on verified_stack, and
* on the unverified_predictions we've made subsequent to
* verified_stack.
*/
GArray *predicted_stack;
/* Idle function used to sync the compositor's view of the window
* stack up with our best guess before a frame is drawn.
*/
guint sync_stack_later;
};
static inline const char *
get_window_desc (MetaStackTracker *tracker,
guint64 window)
{
return meta_display_describe_stack_id (tracker->screen->display, window);
}
static void
meta_stack_op_dump (MetaStackTracker *tracker,
MetaStackOp *op,
const char *prefix,
const char *suffix)
{
const char *window_desc = get_window_desc (tracker, op->any.window);
switch (op->any.type)
{
case STACK_OP_ADD:
meta_topic (META_DEBUG_STACK, "%sADD(%s; %ld)%s",
prefix, window_desc, op->any.serial, suffix);
break;
case STACK_OP_REMOVE:
meta_topic (META_DEBUG_STACK, "%sREMOVE(%s; %ld)%s",
prefix, window_desc, op->any.serial, suffix);
break;
case STACK_OP_RAISE_ABOVE:
{
meta_topic (META_DEBUG_STACK, "%sRAISE_ABOVE(%s, %s; %ld)%s",
prefix,
window_desc,
get_window_desc (tracker, op->raise_above.sibling),
op->any.serial,
suffix);
break;
}
case STACK_OP_LOWER_BELOW:
{
meta_topic (META_DEBUG_STACK, "%sLOWER_BELOW(%s, %s; %ld)%s",
prefix,
window_desc,
get_window_desc (tracker, op->lower_below.sibling),
op->any.serial,
suffix);
break;
}
}
}
static void
stack_dump (MetaStackTracker *tracker,
GArray *stack)
{
guint i;
meta_push_no_msg_prefix ();
for (i = 0; i < stack->len; i++)
{
guint64 window = g_array_index (stack, guint64, i);
meta_topic (META_DEBUG_STACK, " %s", get_window_desc (tracker, window));
}
meta_topic (META_DEBUG_STACK, "\n");
meta_pop_no_msg_prefix ();
}
static void
meta_stack_tracker_dump (MetaStackTracker *tracker)
{
GList *l;
meta_topic (META_DEBUG_STACK, "MetaStackTracker state (screen=%d)\n", tracker->screen->number);
meta_push_no_msg_prefix ();
meta_topic (META_DEBUG_STACK, " xserver_serial: %ld\n", tracker->xserver_serial);
meta_topic (META_DEBUG_STACK, " verified_stack: ");
stack_dump (tracker, tracker->verified_stack);
meta_topic (META_DEBUG_STACK, " unverified_predictions: [");
for (l = tracker->unverified_predictions->head; l; l = l->next)
{
MetaStackOp *op = l->data;
meta_stack_op_dump (tracker, op, "", l->next ? ", " : "");
}
meta_topic (META_DEBUG_STACK, "]\n");
if (tracker->predicted_stack)
{
meta_topic (META_DEBUG_STACK, "\n predicted_stack: ");
stack_dump (tracker, tracker->predicted_stack);
}
meta_pop_no_msg_prefix ();
}
static void
meta_stack_op_free (MetaStackOp *op)
{
g_slice_free (MetaStackOp, op);
}
static int
find_window (GArray *window_stack,
guint64 window)
{
guint i;
for (i = 0; i < window_stack->len; i++)
{
guint64 current = g_array_index (window_stack, guint64, i);
if (current == window)
return i;
}
return -1;
}
/* Returns TRUE if stack was changed */
static gboolean
move_window_above (GArray *stack,
guint64 window,
int old_pos,
int above_pos,
ApplyFlags apply_flags)
{
int i;
gboolean can_restack_this_window =
(apply_flags & NO_RESTACK_X_WINDOWS) == 0 || !META_STACK_ID_IS_X11 (window);
if (old_pos < above_pos)
{
if ((apply_flags & IGNORE_NOOP_X_RESTACK) != 0)
{
gboolean found_x_window = FALSE;
for (i = old_pos + 1; i <= above_pos; i++)
if (META_STACK_ID_IS_X11 (g_array_index (stack, guint64, i)))
found_x_window = TRUE;
if (!found_x_window)
return FALSE;
}
for (i = old_pos; i < above_pos; i++)
{
if (!can_restack_this_window &&
META_STACK_ID_IS_X11 (g_array_index (stack, guint64, i + 1)))
break;
g_array_index (stack, guint64, i) =
g_array_index (stack, guint64, i + 1);
}
g_array_index (stack, guint64, i) = window;
return i != old_pos;
}
else if (old_pos > above_pos + 1)
{
if ((apply_flags & IGNORE_NOOP_X_RESTACK) != 0)
{
gboolean found_x_window = FALSE;
for (i = above_pos + 1; i < old_pos; i++)
if (META_STACK_ID_IS_X11 (g_array_index (stack, guint64, i)))
found_x_window = TRUE;
if (!found_x_window)
return FALSE;
}
for (i = old_pos; i > above_pos + 1; i--)
{
if (!can_restack_this_window &&
META_STACK_ID_IS_X11 (g_array_index (stack, guint64, i - 1)))
break;
g_array_index (stack, guint64, i) =
g_array_index (stack, guint64, i - 1);
}
g_array_index (stack, guint64, i) = window;
return i != old_pos;
}
else
return FALSE;
}
/* Returns TRUE if stack was changed */
static gboolean
meta_stack_op_apply (MetaStackTracker *tracker,
MetaStackOp *op,
GArray *stack,
ApplyFlags apply_flags)
{
switch (op->any.type)
{
case STACK_OP_ADD:
{
if (META_STACK_ID_IS_X11 (op->add.window) &&
(apply_flags & NO_RESTACK_X_WINDOWS) != 0)
return FALSE;
int old_pos = find_window (stack, op->add.window);
if (old_pos >= 0)
{
g_warning ("STACK_OP_ADD: window %s already in stack",
get_window_desc (tracker, op->add.window));
return FALSE;
}
g_array_append_val (stack, op->add.window);
return TRUE;
}
case STACK_OP_REMOVE:
{
if (META_STACK_ID_IS_X11 (op->remove.window) &&
(apply_flags & NO_RESTACK_X_WINDOWS) != 0)
return FALSE;
int old_pos = find_window (stack, op->remove.window);
if (old_pos < 0)
{
g_warning ("STACK_OP_REMOVE: window %s not in stack",
get_window_desc (tracker, op->remove.window));
return FALSE;
}
g_array_remove_index (stack, old_pos);
return TRUE;
}
case STACK_OP_RAISE_ABOVE:
{
int old_pos = find_window (stack, op->raise_above.window);
int above_pos;
if (old_pos < 0)
{
g_warning ("STACK_OP_RAISE_ABOVE: window %s not in stack",
get_window_desc (tracker, op->raise_above.window));
return FALSE;
}
if (op->raise_above.sibling)
{
above_pos = find_window (stack, op->raise_above.sibling);
if (above_pos < 0)
{
g_warning ("STACK_OP_RAISE_ABOVE: sibling window %s not in stack",
get_window_desc (tracker, op->raise_above.sibling));
return FALSE;
}
}
else
{
above_pos = -1;
}
return move_window_above (stack, op->raise_above.window, old_pos, above_pos,
apply_flags);
}
case STACK_OP_LOWER_BELOW:
{
int old_pos = find_window (stack, op->lower_below.window);
int above_pos;
if (old_pos < 0)
{
g_warning ("STACK_OP_LOWER_BELOW: window %s not in stack",
get_window_desc (tracker, op->lower_below.window));
return FALSE;
}
if (op->lower_below.sibling)
{
int below_pos = find_window (stack, op->lower_below.sibling);
if (below_pos < 0)
{
g_warning ("STACK_OP_LOWER_BELOW: sibling window %s not in stack",
get_window_desc (tracker, op->lower_below.sibling));
return FALSE;
}
above_pos = below_pos - 1;
}
else
{
above_pos = stack->len - 1;
}
return move_window_above (stack, op->lower_below.window, old_pos, above_pos,
apply_flags);
}
}
g_assert_not_reached ();
return FALSE;
}
static GArray *
copy_stack (GArray *stack)
{
GArray *copy = g_array_sized_new (FALSE, FALSE, sizeof (guint64), stack->len);
g_array_set_size (copy, stack->len);
memcpy (copy->data, stack->data, sizeof (guint64) * stack->len);
return copy;
}
static void
query_xserver_stack (MetaStackTracker *tracker)
{
MetaScreen *screen = tracker->screen;
Window ignored1, ignored2;
Window *children;
guint n_children;
guint i;
tracker->xserver_serial = XNextRequest (screen->display->xdisplay);
XQueryTree (screen->display->xdisplay,
screen->xroot,
&ignored1, &ignored2, &children, &n_children);
tracker->verified_stack = g_array_sized_new (FALSE, FALSE, sizeof (guint64), n_children);
g_array_set_size (tracker->verified_stack, n_children);
for (i = 0; i < n_children; i++)
g_array_index (tracker->verified_stack, guint64, i) = children[i];
XFree (children);
}
MetaStackTracker *
meta_stack_tracker_new (MetaScreen *screen)
{
MetaStackTracker *tracker;
tracker = g_new0 (MetaStackTracker, 1);
tracker->screen = screen;
query_xserver_stack (tracker);
tracker->unverified_predictions = g_queue_new ();
meta_stack_tracker_dump (tracker);
return tracker;
}
void
meta_stack_tracker_free (MetaStackTracker *tracker)
{
if (tracker->sync_stack_later)
meta_later_remove (tracker->sync_stack_later);
g_array_free (tracker->verified_stack, TRUE);
if (tracker->predicted_stack)
g_array_free (tracker->predicted_stack, TRUE);
g_queue_foreach (tracker->unverified_predictions, (GFunc)meta_stack_op_free, NULL);
g_queue_free (tracker->unverified_predictions);
tracker->unverified_predictions = NULL;
g_free (tracker);
}
static void
stack_tracker_apply_prediction (MetaStackTracker *tracker,
MetaStackOp *op)
{
gboolean free_at_end = FALSE;
/* If this operation doesn't involve restacking X windows then it's
* implicitly verified. We can apply it immediately unless there
* are outstanding X restacks that haven't yet been confirmed.
*/
if (op->any.serial == 0 &&
tracker->unverified_predictions->length == 0)
{
if (meta_stack_op_apply (tracker, op, tracker->verified_stack, APPLY_DEFAULT))
meta_stack_tracker_queue_sync_stack (tracker);
free_at_end = TRUE;
}
else
{
meta_stack_op_dump (tracker, op, "Predicting: ", "\n");
g_queue_push_tail (tracker->unverified_predictions, op);
}
if (!tracker->predicted_stack ||
meta_stack_op_apply (tracker, op, tracker->predicted_stack, APPLY_DEFAULT))
meta_stack_tracker_queue_sync_stack (tracker);
if (free_at_end)
meta_stack_op_free (op);
meta_stack_tracker_dump (tracker);
}
void
meta_stack_tracker_record_add (MetaStackTracker *tracker,
guint64 window,
gulong serial)
{
MetaStackOp *op = g_slice_new (MetaStackOp);
op->any.type = STACK_OP_ADD;
op->any.serial = serial;
op->any.window = window;
stack_tracker_apply_prediction (tracker, op);
}
void
meta_stack_tracker_record_remove (MetaStackTracker *tracker,
guint64 window,
gulong serial)
{
MetaStackOp *op = g_slice_new (MetaStackOp);
op->any.type = STACK_OP_REMOVE;
op->any.serial = serial;
op->any.window = window;
stack_tracker_apply_prediction (tracker, op);
}
static void
meta_stack_tracker_record_raise_above (MetaStackTracker *tracker,
guint64 window,
guint64 sibling,
gulong serial)
{
MetaStackOp *op = g_slice_new (MetaStackOp);
op->any.type = STACK_OP_RAISE_ABOVE;
op->any.serial = serial;
op->any.window = window;
op->raise_above.sibling = sibling;
stack_tracker_apply_prediction (tracker, op);
}
static void
meta_stack_tracker_record_lower_below (MetaStackTracker *tracker,
guint64 window,
guint64 sibling,
gulong serial)
{
MetaStackOp *op = g_slice_new (MetaStackOp);
op->any.type = STACK_OP_LOWER_BELOW;
op->any.serial = serial;
op->any.window = window;
op->lower_below.sibling = sibling;
stack_tracker_apply_prediction (tracker, op);
}
static void
stack_tracker_event_received (MetaStackTracker *tracker,
MetaStackOp *op)
{
gboolean need_sync = FALSE;
/* If the event is older than our initial query, then it's
* already included in our tree. Just ignore it. */
if (op->any.serial < tracker->xserver_serial)
return;
meta_stack_op_dump (tracker, op, "Stack op event received: ", "\n");
/* First we apply any operations that we have queued up that depended
* on X operations *older* than what we received .. those operations
* must have been ignored by the X server, so we just apply the
* operations we have as best as possible while not moving windows.
*/
while (tracker->unverified_predictions->head)
{
MetaStackOp *queued_op = tracker->unverified_predictions->head->data;
if (queued_op->any.serial >= op->any.serial)
break;
meta_stack_op_apply (tracker, queued_op, tracker->verified_stack,
NO_RESTACK_X_WINDOWS);
g_queue_pop_head (tracker->unverified_predictions);
meta_stack_op_free (queued_op);
need_sync = TRUE;
}
/* Then we apply the received event. If it's a spontaneous event
* based on stacking we didn't trigger, this is the only handling. If we
* triggered it, we do the X restacking here, and then any residual
* local-only Wayland stacking below.
*/
if (meta_stack_op_apply (tracker, op, tracker->verified_stack,
IGNORE_NOOP_X_RESTACK))
need_sync = TRUE;
/* What is left to process is the prediction corresponding to the event
* (if any), and then any subsequent Wayland-only events we can just
* go ahead and do now.
*/
while (tracker->unverified_predictions->head)
{
MetaStackOp *queued_op = tracker->unverified_predictions->head->data;
if (queued_op->any.serial > op->any.serial)
break;
meta_stack_op_apply (tracker, queued_op, tracker->verified_stack,
NO_RESTACK_X_WINDOWS);
g_queue_pop_head (tracker->unverified_predictions);
meta_stack_op_free (queued_op);
need_sync = TRUE;
}
if (need_sync)
{
if (tracker->predicted_stack)
{
g_array_free (tracker->predicted_stack, TRUE);
tracker->predicted_stack = NULL;
}
meta_stack_tracker_queue_sync_stack (tracker);
}
meta_stack_tracker_dump (tracker);
}
void
meta_stack_tracker_create_event (MetaStackTracker *tracker,
XCreateWindowEvent *event)
{
MetaStackOp op;
op.any.type = STACK_OP_ADD;
op.any.serial = event->serial;
op.add.window = event->window;
stack_tracker_event_received (tracker, &op);
}
void
meta_stack_tracker_destroy_event (MetaStackTracker *tracker,
XDestroyWindowEvent *event)
{
MetaStackOp op;
op.any.type = STACK_OP_REMOVE;
op.any.serial = event->serial;
op.remove.window = event->window;
stack_tracker_event_received (tracker, &op);
}
void
meta_stack_tracker_reparent_event (MetaStackTracker *tracker,
XReparentEvent *event)
{
if (event->parent == event->event)
{
MetaStackOp op;
op.any.type = STACK_OP_ADD;
op.any.serial = event->serial;
op.add.window = event->window;
stack_tracker_event_received (tracker, &op);
}
else
{
MetaStackOp op;
op.any.type = STACK_OP_REMOVE;
op.any.serial = event->serial;
op.remove.window = event->window;
stack_tracker_event_received (tracker, &op);
}
}
void
meta_stack_tracker_configure_event (MetaStackTracker *tracker,
XConfigureEvent *event)
{
MetaStackOp op;
op.any.type = STACK_OP_RAISE_ABOVE;
op.any.serial = event->serial;
op.raise_above.window = event->window;
op.raise_above.sibling = event->above;
stack_tracker_event_received (tracker, &op);
}
/**
* meta_stack_tracker_get_stack:
* @tracker: a #MetaStackTracker
* @windows: location to store list of windows, or %NULL
* @n_windows: location to store count of windows, or %NULL
*
* @windows will contain the most current view we have of the stacking order
* of the children of the root window. The returned array contains
* everything: InputOnly windows, override-redirect windows,
* hidden windows, etc. Some of these will correspond to MetaWindow
* objects, others won't.
*
* Assuming that no other clients have made requests that change
* the stacking order since we last received a notification, the
* returned list of windows is exactly that you'd get as the
* children when calling XQueryTree() on the root window.
*/
void
meta_stack_tracker_get_stack (MetaStackTracker *tracker,
guint64 **windows,
int *n_windows)
{
GArray *stack;
if (tracker->unverified_predictions->length == 0)
{
stack = tracker->verified_stack;
}
else
{
if (tracker->predicted_stack == NULL)
{
GList *l;
tracker->predicted_stack = copy_stack (tracker->verified_stack);
for (l = tracker->unverified_predictions->head; l; l = l->next)
{
MetaStackOp *op = l->data;
meta_stack_op_apply (tracker, op, tracker->predicted_stack, APPLY_DEFAULT);
}
}
stack = tracker->predicted_stack;
}
if (windows)
*windows = (guint64 *)stack->data;
if (n_windows)
*n_windows = stack->len;
}
/**
* meta_stack_tracker_sync_stack:
* @tracker: a #MetaStackTracker
*
* Informs the compositor of the current stacking order of windows,
* based on the predicted view maintained by the #MetaStackTracker.
*/
void
meta_stack_tracker_sync_stack (MetaStackTracker *tracker)
{
guint64 *windows;
GList *meta_windows;
int n_windows;
int i;
if (tracker->sync_stack_later)
{
meta_later_remove (tracker->sync_stack_later);
tracker->sync_stack_later = 0;
}
meta_stack_tracker_get_stack (tracker, &windows, &n_windows);
meta_windows = NULL;
for (i = 0; i < n_windows; i++)
{
guint64 window = windows[i];
if (META_STACK_ID_IS_X11 (window))
{
MetaWindow *meta_window =
meta_display_lookup_x_window (tracker->screen->display, (Window)window);
/* When mapping back from xwindow to MetaWindow we have to be a bit careful;
* children of the root could include unmapped windows created by toolkits
* for internal purposes, including ones that we have registered in our
* XID => window table. (Wine uses a toplevel for _NET_WM_USER_TIME_WINDOW;
* see window-prop.c:reload_net_wm_user_time_window() for registration.)
*/
if (meta_window &&
((Window)window == meta_window->xwindow ||
(meta_window->frame && (Window)window == meta_window->frame->xwindow)))
meta_windows = g_list_prepend (meta_windows, meta_window);
}
else
meta_windows = g_list_prepend (meta_windows,
meta_display_lookup_stamp (tracker->screen->display, window));
}
meta_compositor_sync_stack (tracker->screen->display->compositor,
meta_windows);
g_list_free (meta_windows);
meta_screen_restacked (tracker->screen);
}
static gboolean
stack_tracker_sync_stack_later (gpointer data)
{
meta_stack_tracker_sync_stack (data);
return FALSE;
}
/**
* meta_stack_tracker_queue_sync_stack:
* @tracker: a #MetaStackTracker
*
* Queue informing the compositor of the new stacking order before the
* next redraw. (See meta_stack_tracker_sync_stack()). This is called
* internally when the stack of X windows changes, but also needs be
* called directly when we an undecorated window is first shown or
* withdrawn since the compositor's stacking order (which contains only
* the windows that have a corresponding MetaWindow) will change without
* any change to the stacking order of the X windows, if we are creating
* or destroying MetaWindows.
*/
void
meta_stack_tracker_queue_sync_stack (MetaStackTracker *tracker)
{
if (tracker->sync_stack_later == 0)
{
tracker->sync_stack_later = meta_later_add (META_LATER_SYNC_STACK,
stack_tracker_sync_stack_later,
tracker, NULL);
}
}
/* When moving an X window we sometimes need an X based sibling.
*
* If the given sibling is X based this function returns it back
* otherwise it searches downwards looking for the nearest X window.
*
* If no X based sibling could be found return NULL. */
static Window
find_x11_sibling_downwards (MetaStackTracker *tracker,
guint64 sibling)
{
guint64 *windows;
int n_windows;
int i;
if (META_STACK_ID_IS_X11 (sibling))
return (Window)sibling;
meta_stack_tracker_get_stack (tracker,
&windows, &n_windows);
/* NB: Children are in order from bottom to top and we
* want to search downwards for the nearest X window.
*/
for (i = n_windows - 1; i >= 0; i--)
if (windows[i] == sibling)
break;
for (; i >= 0; i--)
{
if (META_STACK_ID_IS_X11 (windows[i]))
return (Window)windows[i];
}
return None;
}
static Window
find_x11_sibling_upwards (MetaStackTracker *tracker,
guint64 sibling)
{
guint64 *windows;
int n_windows;
int i;
if (META_STACK_ID_IS_X11 (sibling))
return (Window)sibling;
meta_stack_tracker_get_stack (tracker,
&windows, &n_windows);
for (i = 0; i < n_windows; i++)
if (windows[i] == sibling)
break;
for (; i < n_windows; i++)
{
if (META_STACK_ID_IS_X11 (windows[i]))
return (Window)windows[i];
}
return None;
}
static void
meta_stack_tracker_lower_below (MetaStackTracker *tracker,
guint64 window,
guint64 sibling)
{
gulong serial = 0;
if (META_STACK_ID_IS_X11 (window))
{
XWindowChanges changes;
changes.sibling = sibling ? find_x11_sibling_upwards (tracker, sibling) : None;
if (changes.sibling != find_x11_sibling_upwards (tracker, window))
{
serial = XNextRequest (tracker->screen->display->xdisplay);
meta_error_trap_push (tracker->screen->display);
changes.stack_mode = changes.sibling ? Below : Above;
XConfigureWindow (tracker->screen->display->xdisplay,
window,
(changes.sibling ? CWSibling : 0) | CWStackMode,
&changes);
meta_error_trap_pop (tracker->screen->display);
}
}
meta_stack_tracker_record_lower_below (tracker,
window, sibling,
serial);
}
static void
meta_stack_tracker_raise_above (MetaStackTracker *tracker,
guint64 window,
guint64 sibling)
{
gulong serial = 0;
if (META_STACK_ID_IS_X11 (window))
{
XWindowChanges changes;
changes.sibling = sibling ? find_x11_sibling_downwards (tracker, sibling) : None;
if (changes.sibling != find_x11_sibling_downwards (tracker, window))
{
serial = XNextRequest (tracker->screen->display->xdisplay);
meta_error_trap_push (tracker->screen->display);
changes.stack_mode = changes.sibling ? Above : Below;
XConfigureWindow (tracker->screen->display->xdisplay,
(Window)window,
(changes.sibling ? CWSibling : 0) | CWStackMode,
&changes);
meta_error_trap_pop (tracker->screen->display);
}
}
meta_stack_tracker_record_raise_above (tracker, window,
sibling, serial);
}
void
meta_stack_tracker_lower (MetaStackTracker *tracker,
guint64 window)
{
meta_stack_tracker_raise_above (tracker, window, None);
}
void
meta_stack_tracker_restack_managed (MetaStackTracker *tracker,
const guint64 *managed,
int n_managed)
{
guint64 *windows;
int n_windows;
int old_pos, new_pos;
if (n_managed == 0)
return;
meta_stack_tracker_get_stack (tracker, &windows, &n_windows);
/* If the top window has to be restacked, we don't want to move it to the very
* top of the stack, since apps expect override-redirect windows to stay near
* the top of the X stack; we instead move it above all managed windows (or
* above the guard window if there are no non-hidden managed windows.)
*/
old_pos = n_windows - 1;
for (old_pos = n_windows - 1; old_pos >= 0; old_pos--)
{
MetaWindow *old_window = meta_display_lookup_stack_id (tracker->screen->display, windows[old_pos]);
if ((old_window && !old_window->override_redirect && !old_window->unmanaging) ||
windows[old_pos] == tracker->screen->guard_window)
break;
}
g_assert (old_pos >= 0);
new_pos = n_managed - 1;
if (managed[new_pos] != windows[old_pos])
{
/* Move the first managed window in the new stack above all managed windows */
meta_stack_tracker_raise_above (tracker, managed[new_pos], windows[old_pos]);
meta_stack_tracker_get_stack (tracker, &windows, &n_windows);
/* Moving managed[new_pos] above windows[old_pos], moves the window at old_pos down by one */
}
old_pos--;
new_pos--;
while (old_pos >= 0 && new_pos >= 0)
{
if (windows[old_pos] == tracker->screen->guard_window)
break;
if (windows[old_pos] == managed[new_pos])
{
old_pos--;
new_pos--;
continue;
}
MetaWindow *old_window = meta_display_lookup_stack_id (tracker->screen->display, windows[old_pos]);
if (!old_window || old_window->override_redirect || old_window->unmanaging)
{
old_pos--;
continue;
}
meta_stack_tracker_lower_below (tracker, managed[new_pos], managed[new_pos + 1]);
meta_stack_tracker_get_stack (tracker, &windows, &n_windows);
/* Moving managed[new_pos] above windows[old_pos] moves the window at old_pos down by one,
* we'll examine it again to see if it matches the next new window */
old_pos--;
new_pos--;
}
while (new_pos > 0)
{
meta_stack_tracker_lower_below (tracker, managed[new_pos], managed[new_pos - 1]);
new_pos--;
}
}
void
meta_stack_tracker_restack_at_bottom (MetaStackTracker *tracker,
const guint64 *new_order,
int n_new_order)
{
guint64 *windows;
int n_windows;
int pos;
meta_stack_tracker_get_stack (tracker, &windows, &n_windows);
for (pos = 0; pos < n_new_order; pos++)
{
if (pos >= n_windows || windows[pos] != new_order[pos])
{
if (pos == 0)
meta_stack_tracker_lower (tracker, new_order[pos]);
else
meta_stack_tracker_raise_above (tracker, new_order[pos], new_order[pos - 1]);
meta_stack_tracker_get_stack (tracker, &windows, &n_windows);
}
}
}