textview: use GtkTextViewChild for border and overlay children

This creates a new GtkTextViewChild that can manage overlay children at
given x,y offsets in buffer coordinates. This simplifies GtkTextView by
extracting this from GtkTextWindow as well as providing a real widget for
the borders.

With this change, we also rename gtk_text_view_add_child_in_window() to
gtk_text_view_add_overlay(). For those that were using
GTK_TEXT_WINDOW_WIDGET, they can use a GtkOverlay. It does not appear
that anyone was using GTK_TEXT_WINDOW_(LEFT|RIGHT|TOP|BOTTOM) for widgets
in this fashion, but that can be done by setting a gutter widget with
gtk_text_view_set_gutter(). We can make GtkTextViewChild public if
necessary to simplify this should it become necessary.

GtkTextViewChild will setup a CSS node of either "text" or "border"
depending on the GtkTextWindowType.

The old GtkTextViewChild has been renamed to AnchoredChild as it is only
used for widgets with anchors in the GtkTextBuffer. This also removes the
use of allocated GSList and instead embeds a GQueue and GList to save a
few extraneous allocations.

1 files changed, 516 insertions, 0 deletions

diff --git a/gtk/gtktextviewchild.c b/gtk/gtktextviewchild.c
new file mode 100644
index 0000000000..062424d341
--- /dev/null
+++ b/gtk/gtktextviewchild.c
@@ -0,0 +1,516 @@
+/* -*- Mode: C; c-file-style: "gnu"; tab-width: 8 -*- */
+/* GTK - The GIMP Toolkit
+ * gtk_text_view_child.c Copyright (C) 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "gtkcssnodeprivate.h"
+#include "gtkintl.h"
+#include "gtkprivate.h"
+#include "gtkstylecontext.h"
+#include "gtktextview.h"
+#include "gtktextviewchildprivate.h"
+#include "gtktypebuiltins.h"
+#include "gtkwidgetprivate.h"
+
+typedef struct
+{
+  GList      link;
+  GtkWidget *widget;
+  int        x;
+  int        y;
+} Overlay;
+
+struct _GtkTextViewChild
+{
+  GtkContainer       parent_instance;
+  GtkTextWindowType  window_type;
+  GQueue             overlays;
+  int                xoffset;
+  int                yoffset;
+  GtkWidget         *child;
+};
+
+enum {
+  PROP_0,
+  PROP_WINDOW_TYPE,
+  N_PROPS
+};
+
+G_DEFINE_TYPE (GtkTextViewChild, gtk_text_view_child, GTK_TYPE_CONTAINER)
+
+static GParamSpec *properties[N_PROPS];
+
+static Overlay *
+overlay_new (GtkWidget *widget,
+             int        x,
+             int        y)
+{
+  Overlay *overlay;
+
+  overlay = g_slice_new0 (Overlay);
+  overlay->link.data = overlay;
+  overlay->widget = g_object_ref (widget);
+  overlay->x = x;
+  overlay->y = y;
+
+  return overlay;
+}
+
+static void
+overlay_free (Overlay *overlay)
+{
+  g_assert (overlay->link.prev == NULL);
+  g_assert (overlay->link.next == NULL);
+
+  g_object_unref (overlay->widget);
+  g_slice_free (Overlay, overlay);
+}
+
+static void
+gtk_text_view_child_remove_overlay (GtkTextViewChild *self,
+                                    Overlay          *overlay)
+{
+  g_queue_unlink (&self->overlays, &overlay->link);
+  gtk_widget_unparent (overlay->widget);
+  overlay_free (overlay);
+}
+
+static Overlay *
+gtk_text_view_child_get_overlay (GtkTextViewChild *self,
+                                 GtkWidget        *widget)
+{
+  GList *iter;
+
+  for (iter = self->overlays.head; iter; iter = iter->next)
+    {
+      Overlay *overlay = iter->data;
+
+      if (overlay->widget == widget)
+        return overlay;
+    }
+
+  return NULL;
+}
+
+static void
+gtk_text_view_child_add (GtkContainer *container,
+                         GtkWidget    *widget)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (container);
+
+  if (self->child != NULL)
+    {
+      g_warning ("%s allows a single child and already contains a %s",
+                 G_OBJECT_TYPE_NAME (self),
+                 G_OBJECT_TYPE_NAME (widget));
+      return;
+    }
+
+  self->child = g_object_ref (widget);
+  gtk_widget_set_parent (widget, GTK_WIDGET (self));
+}
+
+static void
+gtk_text_view_child_remove (GtkContainer *container,
+                            GtkWidget    *widget)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (container);
+
+  if (widget == self->child)
+    {
+      self->child = NULL;
+      gtk_widget_unparent (widget);
+      g_object_unref (widget);
+    }
+  else
+    {
+      Overlay *overlay = gtk_text_view_child_get_overlay (self, widget);
+
+      if (overlay != NULL)
+        gtk_text_view_child_remove_overlay (self, overlay);
+    }
+}
+
+static void
+gtk_text_view_child_forall (GtkContainer *container,
+                            GtkCallback   callback,
+                            gpointer      callback_data)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (container);
+  const GList *iter;
+
+  if (self->child != NULL)
+    callback (self->child, callback_data);
+
+  iter = self->overlays.head;
+  while (iter != NULL)
+    {
+      Overlay *overlay = iter->data;
+      iter = iter->next;
+      callback (overlay->widget, callback_data);
+    }
+}
+
+static void
+gtk_text_view_child_measure (GtkWidget      *widget,
+                             GtkOrientation  orientation,
+                             int             for_size,
+                             int            *min_size,
+                             int            *nat_size,
+                             int            *min_baseline,
+                             int            *nat_baseline)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (widget);
+  const GList *iter;
+  int real_min_size = 0;
+  int real_nat_size = 0;
+
+  if (self->child != NULL)
+    gtk_widget_measure (self->child,
+                        orientation,
+                        for_size,
+                        &real_min_size,
+                        &real_nat_size,
+                        NULL,
+                        NULL);
+
+  for (iter = self->overlays.head; iter; iter = iter->next)
+    {
+      Overlay *overlay = iter->data;
+      int child_min_size = 0;
+      int child_nat_size = 0;
+
+      gtk_widget_measure (overlay->widget,
+                          orientation,
+                          for_size,
+                          &child_min_size,
+                          &child_nat_size,
+                          NULL,
+                          NULL);
+
+      if (child_min_size > real_min_size)
+        real_min_size = child_min_size;
+
+      if (child_nat_size > real_nat_size)
+        real_nat_size = child_nat_size;
+    }
+
+  if (min_size)
+    *min_size = real_min_size;
+
+  if (nat_size)
+    *nat_size = real_nat_size;
+
+  if (min_baseline)
+    *min_baseline = -1;
+
+  if (nat_baseline)
+    *nat_baseline = -1;
+}
+
+static void
+gtk_text_view_child_size_allocate (GtkWidget *widget,
+                                   int        width,
+                                   int        height,
+                                   int        baseline)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (widget);
+  GtkRequisition min_req;
+  GdkRectangle rect;
+  const GList *iter;
+
+  GTK_WIDGET_CLASS (gtk_text_view_child_parent_class)->size_allocate (widget, width, height, baseline);
+
+  if (self->child != NULL)
+    {
+      rect.x = 0;
+      rect.y = 0;
+      rect.width = width;
+      rect.height = height;
+
+      gtk_widget_size_allocate (self->child, &rect, baseline);
+    }
+
+  for (iter = self->overlays.head; iter; iter = iter->next)
+    {
+      Overlay *overlay = iter->data;
+
+      gtk_widget_get_preferred_size (overlay->widget, &min_req, NULL);
+
+      rect.width = min_req.width;
+      rect.height = min_req.height;
+
+      if (self->window_type == GTK_TEXT_WINDOW_TEXT ||
+          self->window_type == GTK_TEXT_WINDOW_TOP ||
+          self->window_type == GTK_TEXT_WINDOW_BOTTOM)
+        rect.x = overlay->x - self->xoffset;
+      else
+        rect.x = overlay->x;
+
+      if (self->window_type == GTK_TEXT_WINDOW_TEXT ||
+          self->window_type == GTK_TEXT_WINDOW_RIGHT ||
+          self->window_type == GTK_TEXT_WINDOW_LEFT)
+        rect.y = overlay->y - self->yoffset;
+      else
+        rect.y = overlay->y;
+
+      gtk_widget_size_allocate (overlay->widget, &rect, -1);
+    }
+}
+
+static void
+gtk_text_view_child_snapshot (GtkWidget   *widget,
+                              GtkSnapshot *snapshot)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (widget);
+  const GList *iter;
+
+  GTK_WIDGET_CLASS (gtk_text_view_child_parent_class)->snapshot (widget, snapshot);
+
+  if (self->child)
+    gtk_widget_snapshot_child (widget, self->child, snapshot);
+
+  for (iter = self->overlays.head; iter; iter = iter->next)
+    {
+      Overlay *overlay = iter->data;
+
+      gtk_widget_snapshot_child (widget, overlay->widget, snapshot);
+    }
+}
+
+static void
+gtk_text_view_child_constructed (GObject *object)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (object);
+  GtkCssNode *css_node;
+
+  G_OBJECT_CLASS (gtk_text_view_child_parent_class)->constructed (object);
+
+  css_node = gtk_widget_get_css_node (GTK_WIDGET (self));
+
+  switch (self->window_type)
+    {
+    case GTK_TEXT_WINDOW_LEFT:
+      gtk_css_node_set_name (css_node, "border");
+      gtk_css_node_add_class (css_node, g_quark_from_static_string (GTK_STYLE_CLASS_LEFT));
+      break;
+
+    case GTK_TEXT_WINDOW_RIGHT:
+      gtk_css_node_set_name (css_node, "border");
+      gtk_css_node_add_class (css_node, g_quark_from_static_string (GTK_STYLE_CLASS_RIGHT));
+      break;
+
+    case GTK_TEXT_WINDOW_TOP:
+      gtk_css_node_set_name (css_node, "border");
+      gtk_css_node_add_class (css_node, g_quark_from_static_string (GTK_STYLE_CLASS_TOP));
+      break;
+
+    case GTK_TEXT_WINDOW_BOTTOM:
+      gtk_css_node_set_name (css_node, "border");
+      gtk_css_node_add_class (css_node, g_quark_from_static_string (GTK_STYLE_CLASS_BOTTOM));
+      break;
+
+    case GTK_TEXT_WINDOW_TEXT:
+      gtk_css_node_set_name (css_node, "text");
+      break;
+
+    case GTK_TEXT_WINDOW_WIDGET:
+    default:
+      break;
+    }
+}
+
+static void
+gtk_text_view_child_get_property (GObject    *object,
+                                  guint       prop_id,
+                                  GValue     *value,
+                                  GParamSpec *pspec)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (object);
+
+  switch (prop_id)
+    {
+    case PROP_WINDOW_TYPE:
+      g_value_set_enum (value, self->window_type);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+gtk_text_view_child_set_property (GObject      *object,
+                                  guint         prop_id,
+                                  const GValue *value,
+                                  GParamSpec   *pspec)
+{
+  GtkTextViewChild *self = GTK_TEXT_VIEW_CHILD (object);
+
+  switch (prop_id)
+    {
+    case PROP_WINDOW_TYPE:
+      self->window_type = g_value_get_enum (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+gtk_text_view_child_class_init (GtkTextViewChildClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
+
+  object_class->constructed = gtk_text_view_child_constructed;
+  object_class->get_property = gtk_text_view_child_get_property;
+  object_class->set_property = gtk_text_view_child_set_property;
+
+  widget_class->measure = gtk_text_view_child_measure;
+  widget_class->size_allocate = gtk_text_view_child_size_allocate;
+  widget_class->snapshot = gtk_text_view_child_snapshot;
+
+  container_class->add = gtk_text_view_child_add;
+  container_class->remove = gtk_text_view_child_remove;
+  container_class->forall = gtk_text_view_child_forall;
+
+  /**
+   * GtkTextViewChild:window-type:
+   *
+   * The "window-type" property is the #GtkTextWindowType of the
+   * #GtkTextView that the child is attached.
+   */
+  properties[PROP_WINDOW_TYPE] =
+    g_param_spec_enum ("window-type",
+                       P_("Window Type"),
+                       P_("The GtkTextWindowType"),
+                       GTK_TYPE_TEXT_WINDOW_TYPE,
+                       GTK_TEXT_WINDOW_TEXT,
+                       GTK_PARAM_READWRITE|G_PARAM_CONSTRUCT_ONLY|G_PARAM_EXPLICIT_NOTIFY);
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static void
+gtk_text_view_child_init (GtkTextViewChild *self)
+{
+  self->window_type = GTK_TEXT_WINDOW_TEXT;
+
+  gtk_widget_set_overflow (GTK_WIDGET (self), GTK_OVERFLOW_HIDDEN);
+}
+
+GtkWidget *
+gtk_text_view_child_new (GtkTextWindowType window_type)
+{
+  g_return_val_if_fail (window_type == GTK_TEXT_WINDOW_LEFT ||
+                        window_type == GTK_TEXT_WINDOW_RIGHT ||
+                        window_type == GTK_TEXT_WINDOW_TOP ||
+                        window_type == GTK_TEXT_WINDOW_BOTTOM ||
+                        window_type == GTK_TEXT_WINDOW_TEXT,
+                        NULL);
+
+  return g_object_new (GTK_TYPE_TEXT_VIEW_CHILD,
+                       "window-type", window_type,
+                       NULL);
+}
+
+void
+gtk_text_view_child_add_overlay (GtkTextViewChild *self,
+                                 GtkWidget        *widget,
+                                 int               xpos,
+                                 int               ypos)
+{
+  Overlay *overlay;
+
+  g_return_if_fail (GTK_IS_TEXT_VIEW_CHILD (self));
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  overlay = overlay_new (widget, xpos, ypos);
+  g_queue_push_tail (&self->overlays, &overlay->link);
+  gtk_widget_set_parent (widget, GTK_WIDGET (self));
+}
+
+void
+gtk_text_view_child_move_overlay (GtkTextViewChild *self,
+                                  GtkWidget        *widget,
+                                  int               xpos,
+                                  int               ypos)
+{
+  Overlay *overlay;
+
+  g_return_if_fail (GTK_IS_TEXT_VIEW_CHILD (self));
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  overlay = gtk_text_view_child_get_overlay (self, widget);
+
+  if (overlay != NULL)
+    {
+      overlay->x = xpos;
+      overlay->y = ypos;
+
+      if (gtk_widget_get_visible (GTK_WIDGET (self)) &&
+          gtk_widget_get_visible (widget))
+        gtk_widget_queue_allocate (GTK_WIDGET (self));
+    }
+}
+
+GtkTextWindowType
+gtk_text_view_child_get_window_type (GtkTextViewChild *self)
+{
+  g_return_val_if_fail (GTK_IS_TEXT_VIEW_CHILD (self), 0);
+
+  return self->window_type;
+}
+
+void
+gtk_text_view_child_set_offset (GtkTextViewChild *self,
+                                int               xoffset,
+                                int               yoffset)
+{
+  gboolean changed = FALSE;
+
+  g_return_if_fail (GTK_IS_TEXT_VIEW_CHILD (self));
+
+  if (self->window_type == GTK_TEXT_WINDOW_TEXT ||
+      self->window_type == GTK_TEXT_WINDOW_TOP ||
+      self->window_type == GTK_TEXT_WINDOW_BOTTOM)
+    {
+      if (self->xoffset != xoffset)
+        {
+          self->xoffset = xoffset;
+          changed = TRUE;
+        }
+    }
+
+  if (self->window_type == GTK_TEXT_WINDOW_TEXT ||
+      self->window_type == GTK_TEXT_WINDOW_LEFT ||
+      self->window_type == GTK_TEXT_WINDOW_RIGHT)
+    {
+      if (self->yoffset != yoffset)
+        {
+          self->yoffset = yoffset;
+          changed = TRUE;
+        }
+    }
+
+  if (changed)
+    gtk_widget_queue_draw (GTK_WIDGET (self));
+}