bpo-33768: IDLE: Clicking on code context line moves it to top of editor (GH-7411)

(cherry picked from commit 041272b)

Co-authored-by: Cheryl Sabella <cheryl.sabella@gmail.com>

Author: miss-islington

Lib/idlelib/codecontext.py

@@ -117,6 +117,7 @@ def toggle_code_context_event(self, event=None):
                     height=1,
                     width=1,  # Don't request more than we get.
                     padx=padx, border=border, relief=SUNKEN, state='disabled')
+            self.context.bind('<ButtonRelease-1>', self.jumptoline)
             # Pack the context widget before and above the text_frame widget,
             # thus ensuring that it will appear directly above text_frame.
             self.context.pack(side=TOP, fill=X, expand=False,
@@ -196,6 +197,20 @@ def update_code_context(self):
         self.context.insert('end', '\n'.join(context_strings[showfirst:]))
         self.context['state'] = 'disabled'
 
+    def jumptoline(self, event=None):
+        "Show clicked context line at top of editor."
+        lines = len(self.info)
+        if lines == 1:  # No context lines are showing.
+            newtop = 1
+        else:
+            # Line number clicked.
+            contextline = int(float(self.context.index('insert')))
+            # Lines not displayed due to maxlines.
+            offset = max(1, lines - self.context_depth) - 1
+            newtop = self.info[offset + contextline][0]
+        self.text.yview(f'{newtop}.0')
+        self.update_code_context()
+
     def timer_event(self):
         "Event on editor text widget triggered every UPDATEINTERVAL ms."
         if self.context:

Lib/idlelib/idle_test/test_codecontext.py

@@ -72,6 +72,7 @@ def tearDownClass(cls):
         del cls.root
 
     def setUp(self):
+        self.text.yview(0)
         self.cc = codecontext.CodeContext(self.editor)
 
     def tearDown(self):
@@ -264,6 +265,39 @@ def test_update_code_context(self):
         # context_depth is 1.
         eq(cc.context.get('1.0', 'end-1c'), '    def __init__(self, a, b):')
 
+    def test_jumptoline(self):
+        eq = self.assertEqual
+        cc = self.cc
+        jump = cc.jumptoline
+
+        if not cc.context:
+            cc.toggle_code_context_event()
+
+        # Empty context.
+        cc.text.yview(f'{2}.0')
+        cc.update_code_context()
+        eq(cc.topvisible, 2)
+        cc.context.mark_set('insert', '1.5')
+        jump()
+        eq(cc.topvisible, 1)
+
+        # 4 lines of context showing.
+        cc.text.yview(f'{12}.0')
+        cc.update_code_context()
+        eq(cc.topvisible, 12)
+        cc.context.mark_set('insert', '3.0')
+        jump()
+        eq(cc.topvisible, 8)
+
+        # More context lines than limit.
+        cc.context_depth = 2
+        cc.text.yview(f'{12}.0')
+        cc.update_code_context()
+        eq(cc.topvisible, 12)
+        cc.context.mark_set('insert', '1.0')
+        jump()
+        eq(cc.topvisible, 8)
+
     @mock.patch.object(codecontext.CodeContext, 'update_code_context')
     def test_timer_event(self, mock_update):
         # Ensure code context is not active.

Misc/NEWS.d/next/IDLE/2018-06-04-19-23-11.bpo-33768.I_2qpV.rst

@@ -0,0 +1 @@
+Clicking on a context line moves that line to the top of the editor window.