[gtk: 1/2] textview: Include gutter while computing child allocations

[Matthias Clasen <matthiasc src gnome org>]

commit af5f75aa770538f5d7e77b3b1b6401b853e9cced
Author: JCWasmx86 <JCWasmx86 t-online de>
Date:   Sun Jul 3 09:49:25 2022 +0200

    textview: Include gutter while computing child allocations
    
    The width of the left gutter and the height of the top gutter
    are now used while computing the child allocations for e.g.
    anchors, otherwise - if such a gutter is present - the
    widget would be at the wrong position.
    
    Closes #5016

 gtk/gtktextview.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 57 insertions(+), 7 deletions(-)
---
diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index 6df6b6e50f..bb053696e2 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -4291,7 +4291,9 @@ gtk_text_view_measure (GtkWidget      *widget,
 static void
 gtk_text_view_compute_child_allocation (GtkTextView         *text_view,
                                         const AnchoredChild *vc,
-                                        GtkAllocation       *allocation)
+                                        GtkAllocation       *allocation,
+                                        int                  gutter_width,
+                                        int                  gutter_height)
 {
   int buffer_y;
   GtkTextIter iter;
@@ -4306,8 +4308,8 @@ gtk_text_view_compute_child_allocation (GtkTextView         *text_view,
 
   buffer_y += vc->from_top_of_line;
 
-  allocation->x = vc->from_left_of_buffer - text_view->priv->xoffset;
-  allocation->y = buffer_y - text_view->priv->yoffset;
+  allocation->x = vc->from_left_of_buffer - text_view->priv->xoffset + gutter_width;
+  allocation->y = buffer_y - text_view->priv->yoffset + gutter_height;
 
   gtk_widget_get_preferred_size (vc->widget, &req, NULL);
   allocation->width = req.width;
@@ -4316,11 +4318,13 @@ gtk_text_view_compute_child_allocation (GtkTextView         *text_view,
 
 static void
 gtk_text_view_update_child_allocation (GtkTextView         *text_view,
-                                       const AnchoredChild *vc)
+                                       const AnchoredChild *vc,
+                                       int                  gutter_width,
+                                       int                  gutter_height)
 {
   GtkAllocation allocation;
 
-  gtk_text_view_compute_child_allocation (text_view, vc, &allocation);
+  gtk_text_view_compute_child_allocation (text_view, vc, &allocation, gutter_width, gutter_height);
 
   gtk_widget_size_allocate (vc->widget, &allocation, -1);
 
@@ -4333,6 +4337,44 @@ gtk_text_view_update_child_allocation (GtkTextView         *text_view,
 #endif
 }
 
+static void
+calculate_gutter_offsets (GtkTextView *text_view,
+                          int         *width,
+                          int         *height)
+{
+  GtkWidget *x_gutter;
+  GtkWidget *y_gutter;
+
+  g_return_if_fail (GTK_IS_TEXT_VIEW (text_view));
+  g_return_if_fail (width != NULL && height != NULL);
+
+  x_gutter = gtk_text_view_get_gutter (text_view, GTK_TEXT_WINDOW_LEFT);
+
+  if (x_gutter != NULL)
+    {
+      GtkRequisition x_req = {0};
+      gtk_widget_get_preferred_size (x_gutter, &x_req, NULL);
+      *width = x_req.width;
+    }
+  else
+    {
+      *width = 0;
+    }
+
+  y_gutter = gtk_text_view_get_gutter (text_view, GTK_TEXT_WINDOW_TOP);
+
+  if (y_gutter != NULL)
+    {
+      GtkRequisition y_req = {0};
+      gtk_widget_get_preferred_size (y_gutter, &y_req, NULL);
+      *height = y_req.height;
+    }
+  else
+    {
+      *height = 0;
+    }
+}
+
 static void
 gtk_anchored_child_allocated (GtkTextLayout *layout,
                               GtkWidget     *child,
@@ -4342,6 +4384,10 @@ gtk_anchored_child_allocated (GtkTextLayout *layout,
 {
   AnchoredChild *vc = NULL;
   GtkTextView *text_view = data;
+  int x_offset = 0;
+  int y_offset = 0;
+
+  calculate_gutter_offsets (text_view, &x_offset, &y_offset);
 
   /* x,y is the position of the child from the top of the line, and
    * from the left of the buffer. We have to translate that into text
@@ -4357,7 +4403,7 @@ gtk_anchored_child_allocated (GtkTextLayout *layout,
   vc->from_left_of_buffer = x;
   vc->from_top_of_line = y;
 
-  gtk_text_view_update_child_allocation (text_view, vc);
+  gtk_text_view_update_child_allocation (text_view, vc, x_offset, y_offset);
 }
 
 static void
@@ -4858,6 +4904,10 @@ changed_handler (GtkTextLayout     *layout,
       GtkTextIter first;
       int new_first_para_top;
       int old_first_para_top;
+      int x_offset = 0;
+      int y_offset = 0;
+
+      calculate_gutter_offsets (text_view, &x_offset, &y_offset);
 
       /* If the bottom of the old area was above the top of the
        * screen, we need to scroll to keep the current top of the
@@ -4887,7 +4937,7 @@ changed_handler (GtkTextLayout     *layout,
       for (iter = priv->anchored_children.head; iter; iter = iter->next)
         {
           const AnchoredChild *ac = iter->data;
-          gtk_text_view_update_child_allocation (text_view, ac);
+          gtk_text_view_update_child_allocation (text_view, ac, x_offset, y_offset);
         }
 
       gtk_widget_queue_resize (widget);