Auto-adjust scale and window position when needed.

This is a backport from master to tools_r13

This patch changes the emulator's default behaviour in two ways:

- Automatically compute the window scale to ensure that the emulator's
  window can be displayed within the current screen. This ensures that
  it remains usable when emulating a large-resolution device on a
  small display (e.g. on a 13" laptop running at 1024x768).

  This check and auto-correction do not happen if you use the
  -scale or -dpi-monitor options.

- When re-centering an out-of-focus window, ensure that the top of
  the window is visible (which generally includes the window's
  title bar). This allows the window to be easily moved or minimized
  by the user is needed.

This fixes three bugs:

  http://code.google.com/p/android/issues/detail?id=16399
  http://code.google.com/p/android/issues/detail?id=16398
  http://code.google.com/p/android/issues/detail?id=16397

Change-Id: Ibbc3c8458bd99718e4902d0a032b154c7cff4757
Orig-Change-Id: I8e5a624446d064038b5b9ad16556db8328244906

3 files changed, 59 insertions, 10 deletions

diff --git a/android/qemulator.c b/android/qemulator.c
index b15d751..d29ee94 100644
--- a/android/qemulator.c
+++ b/android/qemulator.c
@@ -330,9 +330,6 @@ get_default_scale( AndroidOptions*  opts )
     if (scale == 0.0 && dpi_monitor > 0)
         scale = dpi_monitor*1.0/dpi_device;
 
-    if (scale == 0.0)
-        scale = 1.0;
-
     return scale;
 }
 
diff --git a/android/skin/window.c b/android/skin/window.c
index 2755763..c1bf23f 100644
--- a/android/skin/window.c
+++ b/android/skin/window.c
@@ -1134,6 +1134,36 @@ skin_window_create( SkinLayout*  slayout, int  x, int  y, double  scale, int  no
 {
     SkinWindow*  window;
 
+    /* If scale is <= 0, we want to check that the window's default size if
+     * not larger than the current screen. Otherwise, we need to compute
+     * a new scale to ensure it is.
+     */
+    if (scale <= 0) {
+        SDL_Rect  monitor;
+        int       screen_w, screen_h;
+        int       win_w = slayout->size.w;
+        int       win_h = slayout->size.h;
+        double    scale_w, scale_h;
+
+        /* To account for things like menu bars, window decorations etc..
+         * We only compute 95% of the real screen size. */
+        SDL_WM_GetMonitorRect(&monitor);
+        screen_w = monitor.w * 0.95;
+        screen_h = monitor.h * 0.95;
+
+        scale_w = 1.0;
+        scale_h = 1.0;
+
+        if (screen_w < win_w && win_w > 1.)
+            scale_w = 1.0 * screen_w / win_w;
+        if (screen_h < win_h && win_h > 1.)
+            scale_h = 1.0 * screen_h / win_h;
+
+        scale = (scale_w <= scale_h) ? scale_w : scale_h;
+
+        VERBOSE_PRINT(init,"autoconfig: -scale %g", scale);
+    }
+
     ANEW0(window);
 
     window->shrink_scale = scale;
@@ -1151,14 +1181,33 @@ skin_window_create( SkinLayout*  slayout, int  x, int  y, double  scale, int  no
     window->y_pos = y;
 
     if (skin_window_reset_internal(window, slayout) < 0) {
-        skin_window_free( window );
+        skin_window_free(window);
         return NULL;
     }
-    //SDL_WM_SetCaption( "Android Emulator", "Android Emulator" );
-
     SDL_WM_SetPos( x, y );
-    if ( !SDL_WM_IsFullyVisible( 1 ) ) {
-        dprint( "emulator window was out of view and was recentred\n" );
+
+    /* Check that the window is fully visible */
+    if ( !window->no_display && !SDL_WM_IsFullyVisible(0) ) {
+        SDL_Rect  monitor;
+        int       win_x, win_y, win_w, win_h;
+        int       new_x, new_y;
+
+        SDL_WM_GetMonitorRect(&monitor);
+        SDL_WM_GetPos(&win_x, &win_y);
+        win_w = window->surface->w;
+        win_h = window->surface->h;
+
+        /* First, we recenter the window */
+        new_x = (monitor.w - win_w)/2;
+        new_y = (monitor.h - win_h)/2;
+
+        /* If it is still too large, we ensure the top-border is visible */
+        if (new_y < 0)
+            new_y = 0;
+
+        /* Done */
+        SDL_WM_SetPos(new_x, new_y);
+        dprint( "emulator window was out of view and was recentered\n" );
     }
 
     return window;
@@ -1316,8 +1365,6 @@ skin_window_reset_internal ( SkinWindow*  window, SkinLayout*  slayout )
     if ( layout_init( &layout, slayout ) < 0 )
         return -1;
 
-    disp = window->layout.displays;
-
     layout_done( &window->layout );
     window->layout = layout;
 
diff --git a/android/skin/window.h b/android/skin/window.h
index 3e92e40..5ba90f5 100644
--- a/android/skin/window.h
+++ b/android/skin/window.h
@@ -18,6 +18,11 @@
 
 typedef struct SkinWindow  SkinWindow;
 
+/* Note: if scale is <= 0, we interpret this as 'auto-detect'.
+ *       The behaviour is to use 1.0 by default, unless the resulting
+ *       window is too large, in which case the window will automatically
+ *       be resized to fit the screen.
+ */
 extern SkinWindow*      skin_window_create( SkinLayout*  layout,
                                             int          x,
                                             int          y,