From 304996d182874ded26adce40ce1c29210fc5352b Mon Sep 17 00:00:00 2001
From: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date: Fri, 11 Apr 2014 13:57:15 +0300
Subject: [PATCH] shell: Fix view repositioning logic for output move and
 destroy

Previously, the repositioning logic would iterate the compositor's list
of layers and move the views on those layers. However, that failed in
two different ways: it didn't cover hidden workspaces and crashed when
the display was locked.

This patch changes the logic to explicit iterate over all the layers
owned by the shell. The iteration is done through a helper function,
shell_for_each_layer().

https://bugs.freedesktop.org/show_bug.cgi?id=76859
https://bugs.freedesktop.org/show_bug.cgi?id=77290
---
 desktop-shell/shell.c | 86 +++++++++++++++++++++++--------------------
 desktop-shell/shell.h |  8 ++++
 2 files changed, 55 insertions(+), 39 deletions(-)

diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index 63b4d4cc2..130618ca6 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -5740,27 +5740,35 @@ shell_reposition_view_on_output_destroy(struct weston_view *view)
 	}
 }
 
-static void
-shell_reposition_views_on_output_destroy(struct shell_output *shell_output)
+void
+shell_for_each_layer(struct desktop_shell *shell,
+		     shell_for_each_layer_func_t func, void *data)
 {
-	struct desktop_shell *shell = shell_output->shell;
-	struct weston_output *output = shell_output->output;
-	struct weston_layer *layer;
+	struct workspace **ws;
+
+	func(shell, &shell->fullscreen_layer, data);
+	func(shell, &shell->panel_layer, data);
+	func(shell, &shell->background_layer, data);
+	func(shell, &shell->lock_layer, data);
+	func(shell, &shell->input_panel_layer, data);
+
+	wl_array_for_each(ws, &shell->workspaces.array)
+		func(shell, &(*ws)->layer, data);
+}
+
+static void
+shell_output_destroy_move_layer(struct desktop_shell *shell,
+				struct weston_layer *layer,
+				void *data)
+{
+	struct weston_output *output = data;
 	struct weston_view *view;
 
-	/* Move all views in the layers owned by the shell */
-	wl_list_for_each(layer, shell->fullscreen_layer.link.prev, link) {
-		wl_list_for_each(view, &layer->view_list, layer_link) {
-			if (view->output != output)
-				continue;
+	wl_list_for_each(view, &layer->view_list, layer_link) {
+		if (view->output != output)
+			continue;
 
-			shell_reposition_view_on_output_destroy(view);
-		}
-
-		/* We don't start from the beggining of the layer list, so
-		 * make sure we don't wrap around it. */
-		if (layer == &shell->background_layer)
-			break;
+		shell_reposition_view_on_output_destroy(view);
 	}
 }
 
@@ -5769,8 +5777,10 @@ handle_output_destroy(struct wl_listener *listener, void *data)
 {
 	struct shell_output *output_listener =
 		container_of(listener, struct shell_output, destroy_listener);
+	struct weston_output *output = output_listener->output;
+	struct desktop_shell *shell = output_listener->shell;
 
-	shell_reposition_views_on_output_destroy(output_listener);
+	shell_for_each_layer(shell, shell_output_destroy_move_layer, output);
 
 	wl_list_remove(&output_listener->destroy_listener.link);
 	wl_list_remove(&output_listener->link);
@@ -5806,34 +5816,32 @@ handle_output_create(struct wl_listener *listener, void *data)
 }
 
 static void
-handle_output_move(struct wl_listener *listener, void *data)
+handle_output_move_layer(struct desktop_shell *shell,
+			 struct weston_layer *layer, void *data)
 {
-	struct desktop_shell *shell;
-	struct weston_output *output;
-	struct weston_layer *layer;
+	struct weston_output *output = data;
 	struct weston_view *view;
 	float x, y;
 
+	wl_list_for_each(view, &layer->view_list, layer_link) {
+		if (view->output != output)
+			continue;
+
+		x = view->geometry.x + output->move_x;
+		y = view->geometry.y + output->move_y;
+		weston_view_set_position(view, x, y);
+	}
+}
+
+static void
+handle_output_move(struct wl_listener *listener, void *data)
+{
+	struct desktop_shell *shell;
+
 	shell = container_of(listener, struct desktop_shell,
 			     output_move_listener);
-	output = data;
 
-	/* Move all views in the layers owned by the shell */
-	wl_list_for_each(layer, shell->fullscreen_layer.link.prev, link) {
-		wl_list_for_each(view, &layer->view_list, layer_link) {
-			if (view->output != output)
-				continue;
-
-			x = view->geometry.x + output->move_x;
-			y = view->geometry.y + output->move_y;
-			weston_view_set_position(view, x, y);
-		}
-
-		/* We don't start from the beggining of the layer list, so
-		 * make sure we don't wrap around it. */
-		if (layer == &shell->background_layer)
-			break;
-	}
+	shell_for_each_layer(shell, handle_output_move_layer, data);
 }
 
 static void
diff --git a/desktop-shell/shell.h b/desktop-shell/shell.h
index 5d127c6d8..4ed11d543 100644
--- a/desktop-shell/shell.h
+++ b/desktop-shell/shell.h
@@ -236,3 +236,11 @@ int
 input_panel_setup(struct desktop_shell *shell);
 void
 input_panel_destroy(struct desktop_shell *shell);
+
+typedef void (*shell_for_each_layer_func_t)(struct desktop_shell *,
+					    struct weston_layer *, void *);
+
+void
+shell_for_each_layer(struct desktop_shell *shell,
+		     shell_for_each_layer_func_t func,
+		     void *data);