bpo-23831: Add moveto method to the tkinter.Canvas widget. (GH-9768)

4 files changed, 38 insertions, 0 deletions

diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst
index d9c3f1bd7d..bd3283caad 100644
--- a/Doc/whatsnew/3.8.rst
+++ b/Doc/whatsnew/3.8.rst
@@ -177,6 +177,10 @@ Added methods :meth:`~tkinter.Spinbox.selection_from`,
 in the :class:`tkinter.Spinbox` class.
 (Contributed by Juliette Monsel in :issue:`34829`.)
 
+Added method :meth:`~tkinter.Canvas.moveto`
+in the :class:`tkinter.Canvas` class.
+(Contributed by Juliette Monsel in :issue:`23831`.)
+
 venv
 ----
 
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py
index fa015ff12e..1dc4118845 100644
--- a/Lib/tkinter/__init__.py
+++ b/Lib/tkinter/__init__.py
@@ -2914,6 +2914,15 @@ class Canvas(Widget, XView, YView):
         """Move an item TAGORID given in ARGS."""
         self.tk.call((self._w, 'move') + args)
 
+    def moveto(self, tagOrId, x='', y=''):
+        """Move the items given by TAGORID in the canvas coordinate
+        space so that the first coordinate pair of the bottommost
+        item with tag TAGORID is located at position (X,Y).
+        X and Y may be the empty string, in which case the
+        corresponding coordinate will be unchanged. All items matching
+        TAGORID remain in the same positions relative to each other."""
+        self.tk.call(self._w, 'moveto', tagOrId, x, y)
+
     def postscript(self, cnf={}, **kw):
         """Print the contents of the canvas to a postscript
         file. Valid options: colormap, colormode, file, fontmap,
diff --git a/Lib/tkinter/test/test_tkinter/test_widgets.py b/Lib/tkinter/test/test_tkinter/test_widgets.py
index c068a9de2d..12a0fbeeee 100644
--- a/Lib/tkinter/test/test_tkinter/test_widgets.py
+++ b/Lib/tkinter/test/test_tkinter/test_widgets.py
@@ -745,6 +745,29 @@ class CanvasTest(AbstractWidgetTest, unittest.TestCase):
         self.checkPixelsParam(widget, 'yscrollincrement',
                               10, 0, 11.2, 13.6, -10, '0.1i')
 
+    @requires_tcl(8, 6)
+    def test_moveto(self):
+        widget = self.create()
+        i1 = widget.create_rectangle(1, 1, 20, 20, tags='group')
+        i2 = widget.create_rectangle(30, 30, 50, 70, tags='group')
+        x1, y1, _, _ = widget.bbox(i1)
+        x2, y2, _, _ = widget.bbox(i2)
+        widget.moveto('group', 200, 100)
+        x1_2, y1_2, _, _ = widget.bbox(i1)
+        x2_2, y2_2, _, _ = widget.bbox(i2)
+        self.assertEqual(x1_2, 200)
+        self.assertEqual(y1_2, 100)
+        self.assertEqual(x2 - x1, x2_2 - x1_2)
+        self.assertEqual(y2 - y1, y2_2 - y1_2)
+        widget.tag_lower(i2, i1)
+        widget.moveto('group', y=50)
+        x1_3, y1_3, _, _ = widget.bbox(i1)
+        x2_3, y2_3, _, _ = widget.bbox(i2)
+        self.assertEqual(y2_3, 50)
+        self.assertEqual(x2_3, x2_2)
+        self.assertEqual(x2_2 - x1_2, x2_3 - x1_3)
+        self.assertEqual(y2_2 - y1_2, y2_3 - y1_3)
+
 
 @add_standard_options(IntegerSizeTests, StandardOptionsTests)
 class ListboxTest(AbstractWidgetTest, unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Library/2018-10-09-15-44-04.bpo-23831.2CL7lL.rst b/Misc/NEWS.d/next/Library/2018-10-09-15-44-04.bpo-23831.2CL7lL.rst
new file mode 100644
index 0000000000..de12407b4f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-10-09-15-44-04.bpo-23831.2CL7lL.rst
@@ -0,0 +1,2 @@
+Add ``moveto()`` method to the ``tkinter.Canvas`` widget. Patch by Juliette
+Monsel.