event-editor/notes-section: Follow AdwEntryRow's style

The current notes text view has had a 2px offset for
an unknown amount of time, due to us magic-numbering
margins and/or padding. This approach works a little
bit differently, in that it uses the `.editable-area`
style class and sets the overlay's CSS name to "box"
to use a predictable size of margins from AdwEntryRow.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/738>

src/gui/event-editor/gcal-notes-section.blp

@@ -2,42 +2,60 @@ using Gtk 4.0;
 using Adw 1;
 
 template $GcalNotesSection: Adw.PreferencesRow {
-  activatable: false;
   focusable: false;
+  selectable: false;
 
   styles [
     "entry",
-    "notes-section",
   ]
 
+  GestureClick {
+    pressed => $on_row_pressed(notes_text) not-swapped;
+  }
+
   child: Overlay {
+    css-name: "box";
+
+    styles [
+      "header",
+    ]
+
     [overlay]
-    Label placeholder {
-      label: _("Notes");
+    Adw.Bin {
       can-focus: false;
       can-target: false;
-      xalign: 0.0;
-      yalign: 0.0;
-      visible: bind $empty_string(notes_text.buffer.text);
 
       styles [
-        "dimmed",
-        "placeholder",
+        "editable-area",
       ]
+
+      child: Label placeholder {
+        label: _("Notes");
+        xalign: 0.0;
+        yalign: 0.0;
+        visible: bind $empty_string(notes_text.buffer.text);
+        margin-top: 12;
+        margin-bottom: 12;
+
+        styles [
+          "dimmed",
+          "placeholder",
+        ]
+      };
     }
 
     child: Adw.Bin {
-      css-name: "box";
+      styles [
+        "editable-area",
+      ]
 
       child: TextView notes_text {
         hexpand: true;
-        top-margin: 6;
-        bottom-margin: 6;
-        left-margin: 6;
-        right-margin: 6;
         sensitive: true;
         wrap-mode: word_char;
         accepts-tab: false;
+        top-margin: 12;
+        bottom-margin: 12;
         state-flags-changed => $on_notes_text_state_flags_changed_cb(template) not-swapped;
 
         accessibility {

src/gui/event-editor/gcal-notes-section.c

@@ -63,6 +63,25 @@ empty_string (gpointer     user_data,
   return g_utf8_strlen (text, -1) == 0;
 }
 
+static void
+on_row_pressed (GtkGestureClick *gesture,
+                gint             n_press,
+                gdouble          x,
+                gdouble          y,
+                GtkWidget       *text_view)
+{
+  GtkWidget *row;
+
+  g_assert (GTK_IS_TEXT_VIEW (text_view));
+
+  row = gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture));
+
+  if (gtk_widget_contains (row, x, y))
+    gtk_widget_grab_focus (text_view);
+
+  gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_NONE);
+}
+
 /*
  * GcalEventEditorSection interface
  */
@@ -165,6 +184,7 @@ gcal_notes_section_class_init (GcalNotesSectionClass *klass)
   gtk_widget_class_bind_template_child (widget_class, GcalNotesSection, placeholder);
 
   gtk_widget_class_bind_template_callback (widget_class, empty_string);
+  gtk_widget_class_bind_template_callback (widget_class, on_row_pressed);
   gtk_widget_class_bind_template_callback (widget_class, on_notes_text_state_flags_changed_cb);
 }
 

src/theme/style.css

@@ -414,10 +414,6 @@ monthpopover > box {
   padding: 8px;
 }
 
-.notes-section label.placeholder {
-  margin: 14px;
-}
-
 .notes-section box > textview > text {
   background: none;
 }