Make canvas.set_logical_size lazy again (#148)

Author: almarklein

rendercanvas/_size.py

@@ -41,27 +41,6 @@ def _resolve_total_pixel_ratio_and_logical_size(self):
 
         self["changed"] = True
 
-    def set_logical_size(self, width: float, height: float):
-        """Called by the canvas when the logical size is set.
-
-        This calculates the expected physical size (with the current pixel ratio),
-        to get the corrected logical size. But this *only* sets the logical_size
-        and total_pixel_ratio. The backend will, likely before the next draw,
-        adjust the size and call set_physical_size(), which re-sets the logical size.
-        """
-        # Calculate adjusted logical size
-        ratio = self["native_pixel_ratio"] * self["canvas_pixel_ratio"]
-        pwidth = max(1, round(float(width) * ratio + 0.01))
-        pheight = max(1, round(float(height) * ratio + 0.01))
-        lwidth, lheight = pwidth / ratio, pheight / ratio
-
-        # Update logical size and total ratio. You could see it as a temporary zoom factor being applied.
-        # Note that The backend will soon call set_physical_size().
-        self["logical_size"] = lwidth, lheight
-        self["total_pixel_ratio"] = self["physical_size"][0] / lwidth
-
-        self["changed"] = True
-
     def set_zoom(self, zoom: float):
         """Set the zoom factor, i.e. the canvas pixel ratio."""
         self["canvas_pixel_ratio"] = float(zoom)

rendercanvas/base.py

@@ -593,8 +593,6 @@ def set_logical_size(self, width: float, height: float) -> None:
         width, height = float(width), float(height)
         if width < 0 or height < 0:
             raise ValueError("Canvas width and height must not be negative")
-        # Already adjust our logical size, so e.g. layout engines can get to work
-        self._size_info.set_logical_size(width, height)
         # Tell the backend to adjust the size. It will likely set the new physical size before the next draw.
         self._rc_set_logical_size(width, height)
 

tests/test_size.py

@@ -31,57 +31,6 @@ def test_size_info_basic():
     assert si["changed"] is True
 
 
-def test_size_info_logical():
-    si = SizeInfo()
-    assert si["physical_size"] == (1, 1)
-    assert si["logical_size"] == (1.0, 1.0)
-    assert si["total_pixel_ratio"] == 1.0
-    assert si["changed"] is False
-
-    # Base class setting logical size
-    si.set_logical_size(100, 100)
-
-    assert si["physical_size"] == (1, 1)  # don't touch!
-    assert si["logical_size"] == (100.0, 100.0)
-    assert si["total_pixel_ratio"] == 0.01
-    assert si["changed"] is True
-
-    # Again
-    si.set_logical_size(640, 480)
-
-    assert si["physical_size"] == (1, 1)  # don't touch!
-    assert si["logical_size"] == (640.0, 480.0)
-    assert si["total_pixel_ratio"] == 1 / 640
-
-    # Now backend adjusts its actual size
-    si.set_physical_size(1280, 960, 2.0)
-
-    assert si["physical_size"] == (1280, 960)
-    assert si["logical_size"] == (640.0, 480.0)
-    assert si["total_pixel_ratio"] == 2.0
-
-    # Base class sets logical size again
-    si.set_logical_size(100.2, 100.2)
-
-    assert si["physical_size"] == (1280, 960)  # don't touch!
-    assert si["logical_size"] == (100.0, 100.0)  # took ratio into account
-    assert si["total_pixel_ratio"] == 1280 / 100
-
-    # And again
-    si.set_logical_size(101.8, 101.8)
-
-    assert si["physical_size"] == (1280, 960)  # don't touch!
-    assert si["logical_size"] == (102.0, 102.0)  # took ratio into account
-    assert si["total_pixel_ratio"] == 1280 / 102
-
-    # And backend adjusts its actual size
-    si.set_physical_size(204, 204, 2.0)
-
-    assert si["physical_size"] == (204, 204)
-    assert si["logical_size"] == (102, 102.0)
-    assert si["total_pixel_ratio"] == 2.0
-
-
 def test_size_info_zoom():
     si = SizeInfo()
     si.set_physical_size(1200, 1200, 2.0)
@@ -145,9 +94,9 @@ def test_canvas_sizing():
 
     c = MyRenderCanvas()
 
-    assert c.get_logical_size() == (640.0, 480.0)
+    assert c.get_logical_size() == (1.0, 1.0)
     assert c.get_physical_size() == (1, 1)
-    assert c.get_pixel_ratio() == 1 / 640
+    assert c.get_pixel_ratio() == 1
 
     c.apply_size()