[gtk+/wip/baedert/progressbar: 5/20] Add GtkGizmo

[Timm Bäder <baedert src gnome org>]

commit 7c580fc5c42d25ac7c67ebe41a62c2701445af63
Author: Timm Bäder <mail baedert org>
Date:   Thu Apr 6 19:17:29 2017 +0200

    Add GtkGizmo
    
    GtkGizmo is the easiest possible widget to implement. It does nothing
    except give its creator a way to control measure/size-allocate/snapshot,
    so it can be used in a variety of use cases.

 gtk/Makefile.am       |    6 +-
 gtk/gtkgizmo.c        |  157 +++++++++++++++++++++++++++++++++++++++++++++++++
 gtk/gtkgizmoprivate.h |   58 ++++++++++++++++++
 3 files changed, 219 insertions(+), 2 deletions(-)
---
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 2b357e3..f66e20b 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -575,7 +575,8 @@ gtk_private_h_sources =             \
        gtkwin32themeprivate.h  \
        gtkwindowprivate.h      \
        gtktreemenu.h           \
-       gdkpixbufutilsprivate.h
+       gdkpixbufutilsprivate.h \
+       gtkgizmoprivate.h
 
 # GTK+ C sources to build the library from
 gtk_base_c_sources =           \
@@ -937,7 +938,8 @@ gtk_base_c_sources =                \
        gtkwindowgroup.c        \
        gtkwin32draw.c          \
        gtkwin32theme.c         \
-       gdkpixbufutils.c
+       gdkpixbufutils.c        \
+       gtkgizmo.c
 
 if USE_QUARTZ
 gtk_base_c_sources +=          \
diff --git a/gtk/gtkgizmo.c b/gtk/gtkgizmo.c
new file mode 100644
index 0000000..5c84012
--- /dev/null
+++ b/gtk/gtkgizmo.c
@@ -0,0 +1,157 @@
+
+#include "gtkgizmoprivate.h"
+#include "gtkwidgetprivate.h"
+#include "gtkcsscustomgadgetprivate.h"
+
+
+G_DEFINE_TYPE (GtkGizmo, gtk_gizmo, GTK_TYPE_WIDGET);
+
+static void
+gtk_gizmo_measure (GtkWidget      *widget,
+                   GtkOrientation  orientation,
+                   int             for_size,
+                   int            *minimum,
+                   int            *natural,
+                   int            *minimum_baseline,
+                   int            *natural_baseline)
+{
+  GtkGizmo *self = GTK_GIZMO (widget);
+
+  gtk_css_gadget_get_preferred_size (self->gadget,
+                                     orientation,
+                                     for_size,
+                                     minimum, natural,
+                                     minimum_baseline, natural_baseline);
+}
+
+static void
+gtk_gizmo_size_allocate (GtkWidget     *widget,
+                         GtkAllocation *allocation)
+{
+  GtkGizmo *self = GTK_GIZMO (widget);
+  GtkAllocation clip;
+
+  GTK_WIDGET_CLASS (gtk_gizmo_parent_class)->size_allocate (widget, allocation);
+
+  gtk_css_gadget_allocate (self->gadget,
+                           allocation,
+                           gtk_widget_get_allocated_baseline (widget),
+                           &clip);
+
+  gtk_widget_set_clip (widget, &clip);
+}
+
+static void
+gtk_gizmo_snapshot (GtkWidget   *widget,
+                    GtkSnapshot *snapshot)
+{
+  GtkGizmo *self = GTK_GIZMO (widget);
+
+  gtk_css_gadget_snapshot (self->gadget, snapshot);
+}
+
+static void
+gtk_gizmo_measure_contents (GtkCssGadget   *gadget,
+                            GtkOrientation  orientation,
+                            int             for_size,
+                            int            *minimum,
+                            int            *natural,
+                            int            *minimum_baseline,
+                            int            *natural_baseline,
+                            gpointer        user_data)
+{
+  GtkGizmo *self = GTK_GIZMO (gtk_css_gadget_get_owner (gadget));
+
+  if (self->measure_func)
+    self->measure_func (self, orientation, for_size,
+                        minimum, natural,
+                        minimum_baseline, natural_baseline);
+}
+
+static void
+gtk_gizmo_allocate_contents (GtkCssGadget        *gadget,
+                             const GtkAllocation *allocation,
+                             int                  baseline,
+                             GtkAllocation       *out_clip,
+                             gpointer             user_data)
+
+{
+  GtkGizmo *self = GTK_GIZMO (gtk_css_gadget_get_owner (gadget));
+
+  if (self->allocate_func)
+    self->allocate_func (self,
+                         allocation,
+                         baseline,
+                         out_clip);
+}
+
+static gboolean
+gtk_gizmo_snapshot_contents (GtkCssGadget *gadget,
+                             GtkSnapshot  *snapshot,
+                             int           x,
+                             int           y,
+                             int           width,
+                             int           height,
+                             gpointer      user_data)
+{
+  GtkGizmo *self = GTK_GIZMO (gtk_css_gadget_get_owner (gadget));
+
+  if (self->snapshot_func)
+    return self->snapshot_func (self, snapshot);
+
+  return FALSE;
+}
+
+static void
+gtk_gizmo_finalize (GObject *obj)
+{
+  GtkGizmo *self = GTK_GIZMO (obj);
+
+  g_clear_object (&self->gadget);
+
+  G_OBJECT_CLASS (gtk_gizmo_parent_class)->finalize (obj);
+}
+
+static void
+gtk_gizmo_class_init (GtkGizmoClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  object_class->finalize = gtk_gizmo_finalize;
+
+  widget_class->measure = gtk_gizmo_measure;
+  widget_class->size_allocate = gtk_gizmo_size_allocate;
+  widget_class->snapshot = gtk_gizmo_snapshot;
+}
+
+static void
+gtk_gizmo_init (GtkGizmo *self)
+{
+  gtk_widget_set_has_window (GTK_WIDGET (self), FALSE);
+
+  self->gadget = gtk_css_custom_gadget_new_for_node (gtk_widget_get_css_node (GTK_WIDGET (self)),
+                                                     GTK_WIDGET (self),
+                                                     gtk_gizmo_measure_contents,
+                                                     gtk_gizmo_allocate_contents,
+                                                     gtk_gizmo_snapshot_contents,
+                                                     NULL,
+                                                     NULL);
+}
+
+GtkWidget *
+gtk_gizmo_new (const char              *css_name,
+               GtkGizmoMeasureFunc  measure_func,
+               GtkGizmoAllocateFunc allocate_func,
+               GtkGizmoSnapshotFunc snapshot_func)
+{
+  GtkGizmo *gizmo = GTK_GIZMO (g_object_new (GTK_TYPE_GIZMO,
+                                             "css-name", css_name,
+                                             NULL));
+
+  gizmo->measure_func  = measure_func;
+  gizmo->allocate_func = allocate_func;
+  gizmo->snapshot_func = snapshot_func;
+
+  return GTK_WIDGET (gizmo);
+}
diff --git a/gtk/gtkgizmoprivate.h b/gtk/gtkgizmoprivate.h
new file mode 100644
index 0000000..5fb7842
--- /dev/null
+++ b/gtk/gtkgizmoprivate.h
@@ -0,0 +1,58 @@
+
+#ifndef __GTK_GIZMO_H__
+#define __GTK_GIZMO_H__
+
+#include "gtkwidget.h"
+#include "gtkcssgadgetprivate.h"
+#include "gtkcsscustomgadgetprivate.h"
+
+#define GTK_TYPE_GIZMO                 (gtk_gizmo_get_type ())
+#define GTK_GIZMO(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_GIZMO, GtkGizmo))
+#define GTK_GIZMO_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), GTK_TYPE_GIZMO, GtkGizmoClass))
+#define GTK_IS_GIZMO(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_GIZMO))
+#define GTK_IS_GIZMO_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_GIZMO))
+#define GTK_GIZMO_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_GIZMO, GtkGizmoClass))
+
+typedef struct _GtkGizmo             GtkGizmo;
+typedef struct _GtkGizmoClass        GtkGizmoClass;
+
+typedef void    (* GtkGizmoMeasureFunc)   (GtkGizmo       *gizmo,
+                                           GtkOrientation  orientation,
+                                           int             for_size,
+                                           int            *minimum,
+                                           int            *natural,
+                                           int            *minimum_baseline,
+                                           int            *natural_baseline);
+typedef void    (* GtkGizmoAllocateFunc)  (GtkGizmo            *gizmo,
+                                           const GtkAllocation *allocation,
+                                           int                  baseline,
+                                           GtkAllocation       *out_clip);
+typedef gboolean (* GtkGizmoSnapshotFunc) (GtkGizmo    *gizmo,
+                                           GtkSnapshot *snapshot);
+
+
+struct _GtkGizmo
+{
+  GtkWidget parent_instance;
+
+  GtkCssGadget *gadget;
+
+  GtkGizmoMeasureFunc  measure_func;
+  GtkGizmoAllocateFunc allocate_func;
+  GtkGizmoSnapshotFunc snapshot_func;
+};
+
+struct _GtkGizmoClass
+{
+  GtkWidgetClass parent_class;
+};
+
+GType      gtk_gizmo_get_type (void) G_GNUC_CONST;
+
+GtkWidget *gtk_gizmo_new (const char          *css_name,
+                          GtkGizmoMeasureFunc  measure_func,
+                          GtkGizmoAllocateFunc allocate_func,
+                          GtkGizmoSnapshotFunc snapshot_func);
+
+
+#endif