bpo-37902: IDLE: Add scrolling for IDLE browsers. (GH-15368)
Modify the wheel event handler so it can also be used for module, path, and stack browsers.
Patch by George Zhang.
(cherry picked from commit 2cd902585815582eb059e3b40e014ebe4e7fdee7)
Co-authored-by: GeeTransit <geetransit@gmail.com>
diff --git a/Lib/idlelib/tree.py b/Lib/idlelib/tree.py
index 21426cb..6229be4 100644
--- a/Lib/idlelib/tree.py
+++ b/Lib/idlelib/tree.py
@@ -56,6 +56,30 @@
column = 0
root.images = images
+def wheel_event(event, widget=None):
+ """Handle scrollwheel event.
+
+ For wheel up, event.delta = 120*n on Windows, -1*n on darwin,
+ where n can be > 1 if one scrolls fast. Flicking the wheel
+ generates up to maybe 20 events with n up to 10 or more 1.
+ Macs use wheel down (delta = 1*n) to scroll up, so positive
+ delta means to scroll up on both systems.
+
+ X-11 sends Control-Button-4,5 events instead.
+
+ The widget parameter is needed so browser label bindings can pass
+ the underlying canvas.
+
+ This function depends on widget.yview to not be overridden by
+ a subclass.
+ """
+ up = {EventType.MouseWheel: event.delta > 0,
+ EventType.ButtonPress: event.num == 4}
+ lines = -5 if up[event.type] else 5
+ widget = event.widget if widget is None else widget
+ widget.yview(SCROLL, lines, 'units')
+ return 'break'
+
class TreeNode:
@@ -260,6 +284,9 @@
anchor="nw", window=self.label)
self.label.bind("<1>", self.select_or_edit)
self.label.bind("<Double-1>", self.flip)
+ self.label.bind("<MouseWheel>", lambda e: wheel_event(e, self.canvas))
+ self.label.bind("<Button-4>", lambda e: wheel_event(e, self.canvas))
+ self.label.bind("<Button-5>", lambda e: wheel_event(e, self.canvas))
self.text_id = id
def select_or_edit(self, event=None):
@@ -410,6 +437,7 @@
# A canvas widget with scroll bars and some useful bindings
class ScrolledCanvas:
+
def __init__(self, master, **opts):
if 'yscrollincrement' not in opts:
opts['yscrollincrement'] = 17
@@ -431,6 +459,9 @@
self.canvas.bind("<Key-Next>", self.page_down)
self.canvas.bind("<Key-Up>", self.unit_up)
self.canvas.bind("<Key-Down>", self.unit_down)
+ self.canvas.bind("<MouseWheel>", wheel_event)
+ self.canvas.bind("<Button-4>", wheel_event)
+ self.canvas.bind("<Button-5>", wheel_event)
#if isinstance(master, Toplevel) or isinstance(master, Tk):
self.canvas.bind("<Alt-Key-2>", self.zoom_height)
self.canvas.focus_set()