Toggle-Drag UI Feature

Dragging on toggle buttons can now be used to press multiple buttons at once, especially useful for layer and outliner buttons.


notes:
- automatically enabled for all toggle buttons
  (may change this if it becomes a problem).
- only buttons of the same type are pressed
  (helps avoid annoyances eg; dragging past layer buttons onto other 3d header buttons and pressing by accident).
- automatic axis locking - dragging will lock to X/Y depending on the initial drag direction,
  makes swipe motions work better, especially with the outliner.


implementation details:
- may re-implement as a region handler (currently its a modal operator).
- checking buttons in-between cursor motion events could be more efficient (but currently works ok).
- button execution needs to be improved
  (currently executing a button thats not under the mouse needed a workaround for passing uiHandleButtonData),
  requires further changes to UI code, will do next.

1 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 648f8bfd8dd..78689c078c6 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -437,6 +437,7 @@ void    uiButSetDragValue(uiBut *but);
 void    uiButSetDragImage(uiBut *but, const char *path, int icon, struct ImBuf *ima, float scale);
 
 int     UI_but_active_drop_name(struct bContext *C);
+struct uiBut  *ui_but_find_mouse_over(struct ARegion *ar, int x, int y);
 
 void    uiButSetFlag(uiBut *but, int flag);
 void    uiButClearFlag(uiBut *but, int flag);
@@ -447,6 +448,8 @@ void    uiButClearDrawFlag(uiBut *but, int flag);
 /* special button case, only draw it when used actively, for outliner etc */
 int     uiButActiveOnly(const struct bContext *C, uiBlock *block, uiBut *but);
 
+void    uiButExecute(const struct bContext *C, uiBut *but);
+
 
 /* Buttons
  *