fix: replace deprecated get_allocation with GTK4 alternatives

Fixes #8

Replace Gtk.Widget.get_allocation() with compute_bounds() for positions
and get_width()/get_height() for dimensions.

Author: vyagh

src/sugar4/activity/activity.py

@@ -906,9 +906,10 @@ def get_preview(self):
             return None
 
         try:
-            # GTK4 approach to getting preview
-            allocation = self.canvas.get_allocation()
-            if allocation.width <= 0 or allocation.height <= 0:
+            # Get canvas dimensions for preview
+            canvas_width = self.canvas.get_width()
+            canvas_height = self.canvas.get_height()
+            if canvas_width <= 0 or canvas_height <= 0:
                 return None
 
             # For GTK4, we need to use a different approach since snapshot()
@@ -918,12 +919,10 @@ def get_preview(self):
             drawing_widget = self._find_drawable_widget(self.canvas)
 
             if drawing_widget and hasattr(drawing_widget, "snapshot"):
-                # Use the drawable widget for preview
-                widget_allocation = drawing_widget.get_allocation()
-                canvas_width, canvas_height = (
-                    widget_allocation.width,
-                    widget_allocation.height,
-                )
+                # Get drawable widget dimensions for preview surface
+                widget_width = drawing_widget.get_width()
+                widget_height = drawing_widget.get_height()
+                canvas_width, canvas_height = widget_width, widget_height
 
                 # Create Cairo surface for the widget
                 screenshot_surface = cairo.ImageSurface(
@@ -937,9 +936,7 @@ def get_preview(self):
                 # Try to render the widget
                 try:
                     snapshot = Gtk.Snapshot()
-                    drawing_widget.snapshot(
-                        snapshot, widget_allocation.width, widget_allocation.height
-                    )
+                    drawing_widget.snapshot(snapshot, widget_width, widget_height)
 
                     # Convert snapshot to cairo surface
                     # For now, we'll create a basic preview

src/sugar4/graphics/palettewindow.py

@@ -1311,7 +1311,6 @@ def draw_rectangle(self, cr, palette):
         if not self.parent:
             return
 
-        allocation = self.parent.get_allocation()
         context = self.parent.get_style_context()
         context.add_class("toolitem")
         context.add_class("palette-down")

src/sugar4/graphics/toolbarbox.py

@@ -438,10 +438,17 @@ def do_snapshot(self, snapshot):
         """Render palette using snapshot drawing."""
         Gtk.Widget.do_snapshot(self, snapshot)
 
-        button_alloc = self._toolbar_button.get_allocation()
+        success, bounds = self._toolbar_button.compute_bounds(self)
+        if success:
+            button_x = bounds.get_x()
+            button_width = bounds.get_width()
+        else:
+            button_x = 0
+            button_width = self._toolbar_button.get_width()
+
         my_width = self.get_width()
 
-        if my_width > 0:
+        if my_width > 0 and button_width > 0:
             color = Gdk.RGBA()
             color.red = 0.7
             color.green = 0.7
@@ -451,15 +458,14 @@ def do_snapshot(self, snapshot):
             line_width = style.FOCUS_LINE_WIDTH * 2
 
             rect1 = Graphene.Rect()
-            rect1.init(0, 0, button_alloc.x + style.FOCUS_LINE_WIDTH, line_width)
+            rect1.init(0, 0, button_x + style.FOCUS_LINE_WIDTH, line_width)
             snapshot.append_color(color, rect1)
 
             rect2 = Graphene.Rect()
             rect2.init(
-                button_alloc.x + button_alloc.width - style.FOCUS_LINE_WIDTH,
+                button_x + button_width - style.FOCUS_LINE_WIDTH,
                 0,
-                my_width
-                - (button_alloc.x + button_alloc.width - style.FOCUS_LINE_WIDTH),
+                my_width - (button_x + button_width - style.FOCUS_LINE_WIDTH),
                 line_width,
             )
             snapshot.append_color(color, rect2)

src/sugar4/graphics/tray.py

@@ -97,16 +97,18 @@ def scroll_to_item(self, item):
             logging.warning("Item not found in tray children")
             return
 
-        # Get the item's allocation
-        allocation = item.get_allocation()
+        success, bounds = item.compute_bounds(self.traybar)
+        if not success:
+            return
+
         if self.orientation == Gtk.Orientation.HORIZONTAL:
             adj = self.get_hadjustment()
-            start = allocation.x
-            stop = allocation.x + allocation.width
+            start = bounds.get_x()
+            stop = bounds.get_x() + bounds.get_width()
         else:
             adj = self.get_vadjustment()
-            start = allocation.y
-            stop = allocation.y + allocation.height
+            start = bounds.get_y()
+            stop = bounds.get_y() + bounds.get_height()
 
         # Scroll if needed
         if start < adj.get_value():
@@ -116,26 +118,28 @@ def scroll_to_item(self, item):
 
     def _scroll_next(self):
         """Scroll to next page."""
-        allocation = self.get_allocation()
         if self.orientation == Gtk.Orientation.HORIZONTAL:
             adj = self.get_hadjustment()
-            new_value = adj.get_value() + allocation.width
-            adj.set_value(min(new_value, adj.get_upper() - allocation.width))
+            width = self.get_width()
+            new_value = adj.get_value() + width
+            adj.set_value(min(new_value, adj.get_upper() - width))
         else:
             adj = self.get_vadjustment()
-            new_value = adj.get_value() + allocation.height
-            adj.set_value(min(new_value, adj.get_upper() - allocation.height))
+            height = self.get_height()
+            new_value = adj.get_value() + height
+            adj.set_value(min(new_value, adj.get_upper() - height))
 
     def _scroll_previous(self):
         """Scroll to previous page."""
-        allocation = self.get_allocation()
         if self.orientation == Gtk.Orientation.HORIZONTAL:
             adj = self.get_hadjustment()
-            new_value = adj.get_value() - allocation.width
+            width = self.get_width()
+            new_value = adj.get_value() - width
             adj.set_value(max(adj.get_lower(), new_value))
         else:
             adj = self.get_vadjustment()
-            new_value = adj.get_value() - allocation.height
+            height = self.get_height()
+            new_value = adj.get_value() - height
             adj.set_value(max(adj.get_lower(), new_value))
 
     def do_get_preferred_width(self):
@@ -164,16 +168,17 @@ def _size_changed_cb(self, widget, pspec):
         self._update_scrollable_state()
 
     def _update_scrollable_state(self):
-        allocation = self.get_allocation()
-        if allocation.width <= 1 and allocation.height <= 1:
+        width = self.get_width()
+        height = self.get_height()
+        if width <= 1 and height <= 1:
             return
 
         traybar_min, traybar_nat = self.traybar.get_preferred_size()
 
         if self.orientation == Gtk.Orientation.HORIZONTAL:
-            scrollable = traybar_nat.width > allocation.width
+            scrollable = traybar_nat.width > width
         else:
-            scrollable = traybar_nat.height > allocation.height
+            scrollable = traybar_nat.height > height
 
         if scrollable != self._scrollable:
             self._scrollable = scrollable