theme: Extend button clickable area to edge of screen

Apply Fitt's law to corner window buttons by extending the clickable
area all the way to the edge of the screen on maximized/tiled windows.
This means that a user moving the pointer all the way to the top-right
corner and clicking, will close the maximized (or right-tiled) window.
The same applies for top-left on maximized and left-tiled windows.

1 files changed, 23 insertions, 2 deletions

diff --git a/src/ui/theme.c b/src/ui/theme.c
index 25d35b1f..60b456a3 100644
--- a/src/ui/theme.c
+++ b/src/ui/theme.c
@@ -1004,7 +1004,17 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
           rect->clickable.height = button_height;
 
           if (i == n_right - 1)
-            rect->clickable.width += layout->right_titlebar_edge + layout->right_width + layout->button_border.right;
+            {
+              /* Extend clickable area to the right edge */
+              rect->clickable.width += layout->right_titlebar_edge + layout->right_width + layout->button_border.right;
+
+              /* For maximized and right-tiled windows, extend clickable area to the top edge (Fitts's law)*/
+              if (flags & META_FRAME_MAXIMIZED || flags & META_FRAME_TILED_RIGHT)
+                {
+                  rect->clickable.y = 0;
+                  rect->clickable.height = button_y + button_height;
+                }
+            }
 
         }
       else
@@ -1035,12 +1045,23 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
       rect->visible.width = button_width;
       rect->visible.height = button_height;
 
-      if (flags & META_FRAME_MAXIMIZED)
+      if (flags & META_FRAME_MAXIMIZED ||
+          flags & META_FRAME_TILED_LEFT ||
+          flags & META_FRAME_TILED_RIGHT)
         {
           rect->clickable.x = rect->visible.x;
           rect->clickable.y = rect->visible.y;
           rect->clickable.width = button_width;
           rect->clickable.height = button_height;
+
+          /* For the first left button on maximized/left-tiled windows, extend to top-left corner (Fitts's law) */
+          if (i == 0 && (flags & META_FRAME_MAXIMIZED || flags & META_FRAME_TILED_LEFT))
+            {
+              rect->clickable.x = 0;
+              rect->clickable.y = 0;
+              rect->clickable.width = rect->visible.x + button_width;
+              rect->clickable.height = button_y + button_height;
+            }
         }
       else
         memmove (&(rect->clickable), &(rect->visible), sizeof(rect->clickable));