Improve the current image viewer implementation

data/halftone.gresource.xml

@@ -23,5 +23,8 @@
     <file preprocess="xml-stripblanks" alias="image-adjust-size-symbolic.svg">icons/scalable/actions/image-adjust-size-symbolic.svg</file>
     <file preprocess="xml-stripblanks" alias="sheet-show-bottom-symbolic.svg">icons/scalable/actions/sheet-show-bottom-symbolic.svg</file>
     <file preprocess="xml-stripblanks" alias="sidebar-show-left-symbolic.svg">icons/scalable/actions/sidebar-show-left-symbolic.svg</file>
+    <file preprocess="xml-stripblanks" alias="zoom-in-symbolic.svg">icons/scalable/actions/zoom-in-symbolic.svg</file>
+    <file preprocess="xml-stripblanks" alias="zoom-original-symbolic.svg">icons/scalable/actions/zoom-original-symbolic.svg</file>
+    <file preprocess="xml-stripblanks" alias="zoom-out-symbolic.svg">icons/scalable/actions/zoom-out-symbolic.svg</file>
   </gresource>
 </gresources>

data/ui/image_view.blp

@@ -89,6 +89,16 @@ template $HalftoneImageView : Adw.Bin {
           ]
         }
 
+        Gtk.Button zoom_reset_button {
+          icon-name: "zoom-original-symbolic";
+          tooltip-text: _("Reset Zoom");
+          action-name: "zoom.best-fit";
+
+          styles [
+            "flat"
+          ]
+        }
+
         Gtk.Button zoom_in_button {
           icon-name: "zoom-in-symbolic";
           tooltip-text: _("Zoom In");
@@ -104,15 +114,11 @@ template $HalftoneImageView : Adw.Bin {
         ]
       }
 
-      child: Gtk.ScrolledWindow viewer_scrolled_window {
+      child: Gtk.ScrolledWindow scrolled_window {
         vexpand: true;
         hexpand: true;
 
-        Gtk.Viewport image_viewport {
-          scroll-to-focus: false;
-
-          child: $HalftoneImage image_widget {};
-        }
+        child: $HalftoneImage image_widget {};
       };
     };
   };

data/ui/shortcuts_dialog.blp

@@ -20,6 +20,11 @@ Adw.ShortcutsDialog shortcuts_dialog {
       accelerator: "<Ctrl>plus plus";
     }
 
+    Adw.ShortcutsItem {
+      title: C_("shortcut window", "Reset Zoom");
+      accelerator: "<Ctrl>0 0";
+    }
+
     Adw.ShortcutsItem {
       title: C_("shortcut window", "Zoom Out");
       accelerator: "<Ctrl>minus minus";

halftone/views/dither_page.py

@@ -301,7 +301,7 @@ def _set_texture(self, path: str, as_original: bool = False) -> None:
 
         texture = GlyGtk4.frame_get_texture(frame)
 
-        current_scale = image_widget.scale
+        current_zoom = image_widget.zoom
         current_scaling_filter = image_widget.scaling_filter
 
         image_widget.texture = texture
@@ -311,7 +311,7 @@ def _set_texture(self, path: str, as_original: bool = False) -> None:
             self.image_options_view.original_texture = texture
         else:
             self.updated_texture = texture
-            image_widget.scale = current_scale
+            image_widget.zoom = current_zoom
             image_widget.scaling_filter = current_scaling_filter
 
     def _get_output_format_suffix(self) -> str: