Allow plugins to process keypress events before Geany (#1829)

In addition, the signal allows plugins swallow the event so it's not
processed by Geany.

doc/pluginsignals.c

@@ -270,3 +270,23 @@ signal void (*update_editor_menu)(GObject *obj, const gchar *word, gint pos, Gea
  */
 signal gboolean (*editor_notify)(GObject *obj, GeanyEditor *editor, SCNotification *nt,
 		gpointer user_data);
+
+/** Sent whenever a key is pressed.
+ *
+ * This signal allows plugins to receive key press events before they are processed
+ * by Geany. Plugins can then process key presses before Geany and decide,
+ * whether Geany should receive the key press event or not.
+ *
+ * @warning This signal should be used carefully. If multiple plugins use this
+ *          signal, the result could be unpredictble depending on which plugin
+ *          receives the signal first.
+ *
+ * @param obj a GeanyObject instance, should be ignored.
+ * @param key The GdkEventKey corresponding to the key press.
+ * @param user_data user data.
+ * @return @c TRUE to stop other handlers from being invoked for the event.
+ *         @c FALSE to propagate the event further.
+ *
+ * @since 1.34
+ */
+signal gboolean (*key_press)(GObject *obj, GdkEventKey *key, gpointer user_data);

src/geanyobject.c

@@ -229,6 +229,15 @@ static void create_signals(GObjectClass *g_object_class)
 		0, NULL, NULL, g_cclosure_marshal_VOID__BOXED,
 		G_TYPE_NONE, 1,
 		G_TYPE_KEY_FILE);
+
+	/* Key press signal */
+	geany_object_signals[GCB_KEY_PRESS_NOTIFY] = g_signal_new (
+		"key-press",
+		G_OBJECT_CLASS_TYPE (g_object_class),
+		G_SIGNAL_RUN_LAST,
+		0, boolean_handled_accumulator, NULL, NULL,
+		G_TYPE_BOOLEAN, 1,
+		GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);
 }
 
 

src/geanyobject.h

@@ -57,6 +57,7 @@ typedef enum
 	GCB_BUILD_START,
 	GCB_SAVE_SETTINGS,
 	GCB_LOAD_SETTINGS,
+	GCB_KEY_PRESS_NOTIFY,
 	GCB_MAX
 }
 GeanyCallbackId;

src/keybindings.c

@@ -38,6 +38,7 @@
 #include "callbacks.h"
 #include "documentprivate.h"
 #include "filetypes.h"
+#include "geanyobject.h"
 #include "keybindingsprivate.h"
 #include "main.h"
 #include "msgwindow.h"
@@ -1350,10 +1351,15 @@ static gboolean on_key_press_event(GtkWidget *widget, GdkEventKey *ev, gpointer
 	GeanyDocument *doc;
 	GeanyKeyGroup *group;
 	GeanyKeyBinding *kb;
+	gboolean key_press_ret;
 
 	if (ev->keyval == 0)
 		return FALSE;
 
+	g_signal_emit_by_name(geany_object, "key-press", ev, &key_press_ret);
+	if (key_press_ret)
+		return TRUE;
+
 	doc = document_get_current();
 	if (doc)
 		document_check_disk_status(doc, FALSE);

src/plugindata.h

@@ -59,7 +59,7 @@ G_BEGIN_DECLS
  * @warning You should not test for values below 200 as previously
  * @c GEANY_API_VERSION was defined as an enum value, not a macro.
  */
-#define GEANY_API_VERSION 236
+#define GEANY_API_VERSION 237
 
 /* hack to have a different ABI when built with GTK3 because loading GTK2-linked plugins
  * with GTK3-linked Geany leads to crash */