texthandle: Fix handle dragging on wayland

Text handles are subsurfaces on wayland, so sort of their own toplevel.
This made gtk_widget_translate_coordinates() to bail out there, resulting
in text handles being mispositioned and jumpy. To fix this, translate to
toplevel GtkWindow coordinates manually, and translate coordinates from
there.

Along the way, the coordinates reported in ::handle-dragged have been
fixed so there is no small jumps in either axis (most noticeable in the
X axis when you started dragging, and in the Y axis when moving between
lines of different heights.

1 files changed, 23 insertions, 8 deletions

diff --git a/gtk/gtktexthandle.c b/gtk/gtktexthandle.c
index da9828728b..83348874b5 100644
--- a/gtk/gtktexthandle.c
+++ b/gtk/gtktexthandle.c
@@ -242,18 +242,33 @@ gtk_text_handle_widget_event (GtkWidget     *widget,
            event->motion.state & GDK_BUTTON1_MASK &&
            priv->windows[pos].dragged)
     {
-      gint x, y, width, handle_height;
+      gint x, y, handle_width, handle_height;
+      cairo_rectangle_int_t rect;
       GtkAllocation allocation;
+      GtkWidget *window;
 
+      window = gtk_widget_get_parent (priv->windows[pos].widget);
       gtk_widget_get_allocation (priv->windows[pos].widget, &allocation);
-      width = allocation.width;
-      _gtk_text_handle_get_size (handle, NULL, &handle_height);
+      _gtk_text_handle_get_size (handle, &handle_width, &handle_height);
+
+      _gtk_window_get_popover_position (GTK_WINDOW (window),
+                                        priv->windows[pos].widget,
+                                        NULL, &rect);
+
+      x = rect.x + event->motion.x - priv->windows[pos].dx;
+      y = rect.y + event->motion.y - priv->windows[pos].dy +
+        priv->windows[pos].border.top / 2;
 
-      x = event->motion.x - priv->windows[pos].dx + (width / 2);
-      y = event->motion.y - priv->windows[pos].dy +
-        priv->windows[pos].pointing_to.height / 2;
+      if (pos == GTK_TEXT_HANDLE_POSITION_CURSOR &&
+          priv->mode == GTK_TEXT_HANDLE_MODE_CURSOR)
+        x += handle_width / 2;
+      else if ((pos == GTK_TEXT_HANDLE_POSITION_CURSOR &&
+                priv->windows[pos].dir == GTK_TEXT_DIR_RTL) ||
+               (pos == GTK_TEXT_HANDLE_POSITION_SELECTION_START &&
+                priv->windows[pos].dir != GTK_TEXT_DIR_RTL))
+        x += handle_width;
 
-      gtk_widget_translate_coordinates (widget, priv->parent, x, y, &x, &y);
+      gtk_widget_translate_coordinates (window, priv->parent, x, y, &x, &y);
       g_signal_emit (handle, signals[HANDLE_DRAGGED], 0, pos, x, y);
     }
 
@@ -400,7 +415,7 @@ _gtk_text_handle_update (GtkTextHandle         *handle,
         rect.x -= rect.width;
 
       border->top = height;
-      border->bottom = handle_window->pointing_to.height;
+      border->bottom = height;
 
       /* The goal is to make the window 3 times as wide and high. The handle
        * will be rendered in the center, making the rest an invisible border.