Sticky Keys backend

Design task: T42339
Differential Revision: D840
Initial implementation proposal: T41867

Short description:
With this we can distinguish between holding and tabbing a key. Useful
is this if we want to assign to operators to a single shortcut. If two
operators are assigned to one shortcut, we call this a sticky key.

More info is accessible through the design task and the diff.

A few people that were involved with this:
* Sean Olson for stressing me with this burden ;) - It is his enthusiasm
that pushed me forward to get this done
* Campbell and Antony for the code and design review
* Ton for the design review
* All the other people that gave feedback on the patch and helped to
make this possible

A big "Thank You" for you all!

1 files changed, 9 insertions, 4 deletions

diff --git a/release/scripts/startup/bl_ui/space_userpref.py b/release/scripts/startup/bl_ui/space_userpref.py
index 3b17e40c294..04020d0a1bb 100644
--- a/release/scripts/startup/bl_ui/space_userpref.py
+++ b/release/scripts/startup/bl_ui/space_userpref.py
@@ -1055,6 +1055,15 @@ class USERPREF_PT_input(Panel):
         subrow.menu("USERPREF_MT_interaction_presets", text=bpy.types.USERPREF_MT_interaction_presets.bl_label)
         subrow.operator("wm.interaction_preset_add", text="", icon='ZOOMIN')
         subrow.operator("wm.interaction_preset_add", text="", icon='ZOOMOUT').remove_active = True
+
+        sub.separator()
+
+        sub = col.column()
+        sub.label(text="Double Click:")
+        sub.prop(inputs, "double_click_time", text="Speed")
+        sub.label(text="Sticky Keys:")
+        sub.prop(inputs, "click_timeout")
+
         sub.separator()
 
         sub.label(text="Mouse:")
@@ -1068,10 +1077,6 @@ class USERPREF_PT_input(Panel):
         sub.label(text="Select With:")
         sub.row().prop(inputs, "select_mouse", expand=True)
 
-        sub = col.column()
-        sub.label(text="Double Click:")
-        sub.prop(inputs, "mouse_double_click_time", text="Speed")
-
         sub.separator()
 
         sub.prop(inputs, "use_emulate_numpad")