Implement Mouse Gestures extension

AUTHORS

@@ -13,6 +13,7 @@ Contributors:
     Alexander Hesse <alex@phicode.de>
     Brian Vuyk <brian@brianvuyk.com>
     Nick Schermer <nick@xfce.org>
+    Matthias Kruk <mkruk@matthiaskruk.de>
 
 Graphics:
     extension: Nancy Runge <nancy@twotoasts.de>

extensions/mouse-gestures/main.c

@@ -0,0 +1,229 @@
+/*
+ Copyright (C) 2009 Matthias Kruk <mkruk@matthiaskruk.de>
+
+ 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 2.1 of the License, or (at your option) any later version.
+
+ See the file COPYING for the full license text.
+*/
+
+#include <midori/midori.h>
+#include "mouse-gestures.h"
+
+#define MOUSE_GESTURES_VERSION "0.1"
+#define DEVIANCE 20 // the deviance to determine if a line is straight or not
+#define MINLENGTH 50 // the minimal length of a line to be treated as a gesture
+
+// #define __MOUSE_GESTURES_DEBUG__ // uncomment for debugging purposes
+
+MouseGesture *gesture;
+
+void mouse_gesture_clear(MouseGesture *g)
+{
+	g->start.x = 0;
+	g->start.y = 0;
+	g->middle.x = 0;
+	g->middle.y = 0;
+	g->end.x = 0;
+	g->end.y = 0;
+	g->last = MOUSE_BUTTON_UNSET;
+	return;
+}
+
+MouseGesture* mouse_gesture_new(void)
+{
+	MouseGesture *g = NULL;
+	if((g = g_new(MouseGesture, 1)) == NULL)
+		return(NULL);
+	mouse_gesture_clear(g);
+	return(g);
+}
+
+static gboolean mouse_gestures_handle_events(GtkWidget *widget, GdkEvent *event, MidoriBrowser *browser)
+{
+	if(event->type == GDK_BUTTON_PRESS) // a button was pressed
+	{
+		if(gesture->last == MOUSE_BUTTON_UNSET) // if the gesture was previously cleaned -> new gesture -> new start coordinates
+		{
+			gesture->start.x = event->button.x;
+			gesture->start.y = event->button.y;
+			gesture->last = event->button.button;
+		}
+		return(TRUE);
+	}
+	else if(event->type == GDK_MOTION_NOTIFY) // the mouse was moved
+	{
+		if(gesture->last != MOUSE_BUTTON_UNSET)
+		{
+			guint x, y;
+			x = event->motion.x;
+			y = event->motion.y;
+			if((gesture->start.x - x < DEVIANCE && gesture->start.x - x > -DEVIANCE) ||
+			   (gesture->start.y - y < DEVIANCE && gesture->start.y - y > -DEVIANCE))
+			{
+				gesture->middle.x = x;
+				gesture->middle.y = y;
+			}
+			else if((gesture->middle.x - x < DEVIANCE && gesture->middle.x - x > -DEVIANCE) ||
+			   (gesture->middle.y - y < DEVIANCE && gesture->middle.y - y > -DEVIANCE))
+			{
+				gesture->end.x = x;
+				gesture->end.y = y;
+			}
+		}
+		return(TRUE);
+	}
+	else if(event->type == GDK_BUTTON_RELEASE)
+	{
+		if(gesture->last == MOUSE_BUTTON_MIDDLE) // all mouse gestures will use the middle mouse button
+		{
+			// middle mouse button has been released
+			if(gesture->middle.x - gesture->start.x < DEVIANCE && gesture->middle.x - gesture->start.x > -DEVIANCE)
+			{
+				// StartNode to MiddleNode is a straight vertical line
+				if(gesture->middle.y > gesture->start.y + MINLENGTH)
+				{
+					// StartNode to MiddleNode is drawn downwards
+					if(gesture->middle.y - gesture->end.y < DEVIANCE && gesture->middle.y - gesture->end.y > -DEVIANCE && gesture->end.x > gesture->middle.x + MINLENGTH)
+					{
+						// MiddleNode to EndNode is a straight horizontal line (to the right) -> close tab
+						midori_browser_activate_action(browser, "TabClose");
+						#ifdef __MOUSE_GESTURES_DEBUG__
+						g_print("TabClose gesture\n");
+						#endif
+					}
+					else if(gesture->middle.y - gesture->end.y < DEVIANCE && gesture->middle.y - gesture->end.y > -DEVIANCE && gesture->end.x < gesture->middle.x - MINLENGTH)
+					{
+						// MiddleNode to EndNode is a straight horizontal line (to the left) -> reload
+						midori_browser_activate_action(browser, "Reload");
+						#ifdef __MOUSE_GESTURES_DEBUG__
+						g_print("Reload gesture\n");
+						#endif
+					}
+					else if(gesture->end.y == 0 && gesture->end.x == 0)
+					{
+						// no EndNode, just a vertical line -> new tab
+						midori_browser_activate_action(browser, "TabNew");
+						#ifdef __MOUSE_GESTURES_DEBUG__
+						g_print("TabNew gesture\n");
+						#endif
+					}
+				}
+				if(gesture->middle.y < gesture->start.y - MINLENGTH)
+				{
+					// StartNode to MiddleNode is drawn upwards
+					if(gesture->end.y == 0 && gesture->end.x == 0)
+					{
+						// no EndNode, just a vertical line -> stop
+						midori_browser_activate_action(browser, "Stop");
+						#ifdef __MOUSE_GESTURES_DEBUG__
+						g_print("Stop gesture\n");
+						#endif
+					}
+				}
+			}
+			else if(gesture->middle.y - gesture->start.y < DEVIANCE && gesture->middle.y - gesture->start.y > -DEVIANCE)
+			{
+				// Start Node to MiddleNode is a straight horizontal line
+				if(gesture->middle.x > gesture->start.x + MINLENGTH)
+				{
+					// the line was drawn from left to right
+					if(gesture->end.x == 0 && gesture->end.y == 0)
+					{
+						// we only have one horizontal line from left to right -> forward gesture
+						midori_browser_activate_action(browser, "Forward");
+						#ifdef __MOUSE_GESTURES_DEBUG__
+						g_print("Forward gesture\n");
+						#endif
+					}
+				}
+				else if(gesture->middle.x < gesture->start.x - MINLENGTH)
+				{
+					// the line was drawn from right to left
+					if(gesture->end.x == 0 && gesture->end.y == 0)
+					{
+						// we only have one horizontal line from right to left -> backwards gesture
+						midori_browser_activate_action(browser, "Back");
+						#ifdef __MOUSE_GESTURES_DEBUG__
+						g_print("Back gesture\n");
+						#endif
+					}
+				}
+			}
+		}
+		mouse_gesture_clear(gesture); // gesture finished, clear it
+		return(TRUE);
+	}
+	else
+		return(FALSE); // this event is supposed to be handled again (by someone else's code) since it was irrelevant to us
+}
+
+static void mouse_gestures_tab_cb(MidoriBrowser* browser, GtkWidget *view) // this is performed when a new tab is created
+{
+	g_signal_connect(view, "event", G_CALLBACK(mouse_gestures_handle_events), browser); // perform the above callback when an event from the view is received
+	return;
+}
+
+static void mouse_gestures_browser_cb(MidoriApp *app, MidoriBrowser *browser) // this is performed when ever a new window is created
+{
+	g_signal_connect(browser, "add-tab", G_CALLBACK(mouse_gestures_tab_cb), NULL); // connect the above callback to the "add-tab" signal of browser
+	return;
+}
+
+/* this is performed when the extension is deactivated.
+   disconnect all signal handlers, so that mouse gestures are no longer handled */
+static void mouse_gestures_deactivate(MidoriExtension *extension, MidoriApp *app)
+{
+	gulong signal_id = g_signal_handler_find(app, G_SIGNAL_MATCH_FUNC, 0, 0, NULL, mouse_gestures_browser_cb, NULL); // get the signal handler id
+	if(signal_id != 0) // if that id is valid
+		g_signal_handler_disconnect(app, signal_id); // disconnect the signal
+	KatzeArray *browsers = katze_object_get_object(app, "browsers"); // get the array that contains all browsers
+	guint i; // our counter variable :)
+	for(i = 0; i < katze_array_get_length(browsers); i++) // from the first to the last browser
+	{
+		MidoriBrowser *browser = katze_array_get_nth_item(browsers, i); // get a pointer on the current browser
+		signal_id = g_signal_handler_find(browser, G_SIGNAL_MATCH_FUNC, 0, 0, NULL, mouse_gestures_tab_cb, NULL); // search forthe signal handler id
+		if(signal_id != 0) // and if its not invalid..
+			g_signal_handler_disconnect(browser, signal_id); // disconnect it
+
+		GtkWidget *notebook = katze_object_get_object(browser, "notebook"); // get a pointer on the notebook
+		gint j; // another counter
+		for(j = 0; j < gtk_notebook_get_n_pages(GTK_NOTEBOOK(notebook)); j++) // from the first to the last tab
+		{
+			GtkWidget *page = gtk_notebook_get_nth_page(GTK_NOTEBOOK(notebook), j); // get a pointer on the tab's view
+			signal_id = g_signal_handler_find(page, G_SIGNAL_MATCH_FUNC, 0, 0, NULL, mouse_gestures_handle_events, NULL); // find the signal id of the event handler
+			if(signal_id != 0) // if the id is valid
+				g_signal_handler_disconnect(page, signal_id); // disconnect the handler
+		}
+	}
+	g_free(gesture); // free the structure that contains the gesture information
+	return;
+}
+
+static void mouse_gestures_activate(MidoriExtension *extension, MidoriApp *app) // this is performed on extension-activation
+{
+    g_signal_connect(app, "add-browser", G_CALLBACK(mouse_gestures_browser_cb), NULL); // connect the above callback to the "add-browser" signal of app
+	g_signal_connect(extension, "deactivate", G_CALLBACK(mouse_gestures_deactivate), app); // connect the deactivate callback to the extension
+	return;
+}
+
+MidoriExtension* extension_init(void)
+{
+    MidoriExtension* extension = NULL;
+	extension = g_object_new(MIDORI_TYPE_EXTENSION,
+							 "name", "Mouse gestures",
+							 "description", "Control Midori by moving the mouse",
+							 "version", MOUSE_GESTURES_VERSION,
+							 "authors", "Matthias Kruk <mkruk@matthiaskruk.de>", NULL);
+    g_signal_connect(extension, "activate", G_CALLBACK(mouse_gestures_activate), NULL); // connect the callback that's executed on activation
+	gesture = NULL; // initialise gesture pointer; initialising pointers is always a good choice
+	if((gesture = mouse_gesture_new()) == NULL) // allocate space for the gesture
+	{
+		// no space could be allocated
+		g_free(extension); // free the space used by this extension
+		return(NULL);
+	}
+    return(extension);
+}

extensions/mouse-gestures/mouse-gestures.h

@@ -0,0 +1,37 @@
+/*
+ Copyright (C) 2009 Matthias Kruk <mkruk@matthiaskruk.de>
+
+ 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 2.1 of the License, or (at your option) any later version.
+
+ See the file COPYING for the full license text.
+*/
+
+#ifndef __MOUSE_GESTURES_H__
+#define __MOUSE_GESTURES_H__
+
+typedef struct _MouseGesture MouseGesture;
+typedef enum _MouseButton MouseButton;
+
+enum _MouseButton {
+	MOUSE_BUTTON_LEFT = 1,
+	MOUSE_BUTTON_RIGHT = 3,
+	MOUSE_BUTTON_MIDDLE = 2,
+	MOUSE_BUTTON_UNSET = 0
+};
+
+struct MouseGestureNode {
+	double x;
+	double y;
+} MouseGestureNode_t;
+
+struct _MouseGesture {
+	struct MouseGestureNode start;
+	struct MouseGestureNode middle;
+	struct MouseGestureNode end;
+	MouseButton last;
+};
+
+#endif