[gtksourceview/wip/chergert/gsv-gtk4] gutter: work around recent GdkEvent changes

[Christian Hergert <chergert src gnome org>]

commit 28dd6920208b962512f339c320d1571f43e66d6d
Author: Christian Hergert <chergert redhat com>
Date:   Mon Mar 16 12:16:04 2020 -0700

    gutter: work around recent GdkEvent changes
    
    This is a minimal port to work more like the old API, but eventually we
    would want to get rid of all of this in favor of widgets per row (once
    that can be made fast and recycle widgetry).

 gtksourceview/gtksourcegutter.c | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)
---
diff --git a/gtksourceview/gtksourcegutter.c b/gtksourceview/gtksourcegutter.c
index 99068510..21384297 100644
--- a/gtksourceview/gtksourcegutter.c
+++ b/gtksourceview/gtksourcegutter.c
@@ -1006,6 +1006,38 @@ renderer_query_activatable (GtkSourceGutter *gutter,
        return gtk_source_gutter_renderer_query_activatable (renderer->renderer, &iter, &r);
 }
 
+static gboolean
+get_button (GdkEvent *event,
+            guint    *button)
+{
+       GdkEventType type;
+
+       g_assert (event != NULL);
+       g_assert (button != NULL);
+
+       type = gdk_event_get_event_type (event);
+
+       if (type == GDK_BUTTON_PRESS || type == GDK_BUTTON_RELEASE)
+       {
+               *button = gdk_button_event_get_button (event);
+               return TRUE;
+       }
+
+       return FALSE;
+}
+
+static gboolean
+get_modifier_state (GdkEvent        *event,
+                    GdkModifierType *state)
+{
+       g_assert (event != NULL);
+       g_assert (state != NULL);
+
+       *state = gdk_event_get_modifier_state (event);
+
+       return TRUE;
+}
+
 static void
 on_gutter_pressed_cb (GtkSourceGutter *gutter,
                       gint             n_presses,
@@ -1013,7 +1045,7 @@ on_gutter_pressed_cb (GtkSourceGutter *gutter,
                       gdouble          y,
                       GtkGestureClick *click)
 {
-       const GdkEvent *last_event;
+       GdkEvent *last_event;
        Renderer *renderer;
        GtkTextIter line_iter;
        GdkRectangle rect;
@@ -1026,8 +1058,8 @@ on_gutter_pressed_cb (GtkSourceGutter *gutter,
        last_event = gtk_gesture_get_last_event (GTK_GESTURE (click), NULL);
 
        if (last_event == NULL ||
-           !gdk_event_get_state (last_event, &state) ||
-           !gdk_event_get_button (last_event, &button))
+           !get_modifier_state (last_event, &state) ||
+           !get_button (last_event, &button))
        {
                return;
        }