Implement Canvas Size feature

addon/operators.py

@@ -1,5 +1,5 @@
 '''
-    Copyright (C) 2021 - 2023 Akaneyu
+    Copyright (C) 2021 - 2024 Akaneyu
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -764,6 +764,77 @@ class IMAGE_EDITOR_PLUS_OT_scale(bpy.types.Operator):
 
         return {'FINISHED'}
 
+class IMAGE_EDITOR_PLUS_OT_change_canvas_size(bpy.types.Operator):
+    """Apply settings"""
+    bl_idname = "image_editor_plus.change_canvas_size"
+    bl_label = "Change Canvas Size"
+    width: bpy.props.IntProperty()
+    height: bpy.props.IntProperty()
+    expand_from_center: bpy.props.BoolProperty()
+    use_background_color: bpy.props.BoolProperty()
+
+    def execute(self, context):
+        wm = context.window_manager
+
+        props = wm.imageeditorplus_properties
+        if self.use_background_color:
+            color = props.background_color[:] + (1.0,)
+        else:
+            color = (0, 0, 0, 0)
+
+        img = context.area.spaces.active.image
+        if not img:
+            return {'CANCELLED'}
+
+        width, height = img.size
+        pixels = utils.read_pixels_from_image(img)
+
+        if self.width > width or self.height > height:
+            expand_width = self.width - width if self.width > width else 0
+            expand_height = self.height - height if self.height > height else 0
+
+            if self.expand_from_center:
+                expand_left = int(expand_width / 2)
+                expand_top = int(expand_height / 2)
+                expand_right = expand_width - expand_left
+                expand_bottom = expand_height - expand_top
+            else:
+                expand_left, expand_top = 0, 0
+                expand_right = expand_width
+                expand_bottom = expand_height
+
+            new_pixels = np.pad(pixels, ((expand_bottom, expand_top),
+                    (expand_left, expand_right), (0, 0)),
+                    constant_values=np.array(((color, color), (color, color), (0, 0)),
+                    dtype=object))
+        else:
+            new_pixels = pixels
+
+        if self.width < width or self.height < height:
+            shrink_width = width - self.width if self.width < width else 0
+            shrink_height = height - self.height if self.height < height else 0
+
+            if self.expand_from_center:
+                shrink_left = int(shrink_width / 2)
+                shrink_top = int(shrink_height / 2)
+            else:
+                shrink_left, shrink_top = 0, 0
+
+            if self.height < height:
+                new_pixels = new_pixels[height - self.height - shrink_top:height - shrink_top,
+                        shrink_left:self.width + shrink_left]
+            else:
+                new_pixels = new_pixels[0:self.height,
+                        shrink_left:self.width + shrink_left]
+
+        img.scale(self.width, self.height)
+
+        utils.write_pixels_to_image(img, new_pixels)
+
+        app.refresh_image(context)
+
+        return {'FINISHED'}
+
 class IMAGE_EDITOR_PLUS_OT_flip_layer(bpy.types.Operator):
     """Flip the layer"""
     bl_idname = "image_editor_plus.flip_layer"