Add mouse gestures

Add mouse gestures using GtkEventControllerMotion with two functions:
  - Middle click + Move left = Go back
  - Middle click + Move right = Go forward
  - Middle click + Move down = Open a new tab
  - Middle click + Move up + Move down = Reload current tab
  - Middle click + Move down + Move right = Close current tab

Fixes: https://gitlab.gnome.org/GNOME/epiphany/issues/430

6 files changed, 379 insertions, 1 deletions

diff --git a/data/org.gnome.epiphany.gschema.xml b/data/org.gnome.epiphany.gschema.xml
index 3e8af4305..6e0b225d5 100644
--- a/data/org.gnome.epiphany.gschema.xml
+++ b/data/org.gnome.epiphany.gschema.xml
@@ -249,6 +249,11 @@
 			<summary>Enable autosearch</summary>
 			<description>Whether to automatically search the web when something that does not look like a URL is entered in the address bar. If this setting is disabled, everything will be loaded as a URL unless a search engine is explicitly selected from the dropdown menu.</description>
 		</key>
+		<key type="b" name="enable-mouse-gestures">
+			<default>false</default>
+			<summary>Enable mouse gesture</summary>
+			<description>Whether to enable mouse gestures. Mouse gestures are based on Opera's behaviour and are activated using the middle mouse button + gesture.</description>
+		</key>
 	</schema>
         <schema id="org.gnome.Epiphany.webapp">
                 <key type="as" name="additional-urls">
diff --git a/lib/ephy-prefs.h b/lib/ephy-prefs.h
index 0dad6b131..d5568a156 100644
--- a/lib/ephy-prefs.h
+++ b/lib/ephy-prefs.h
@@ -119,6 +119,7 @@ static const char * const ephy_prefs_state_schema[] = {
 #define EPHY_PREFS_WEB_GSB_API_KEY                 "gsb-api-key"
 #define EPHY_PREFS_WEB_DEFAULT_ZOOM_LEVEL          "default-zoom-level"
 #define EPHY_PREFS_WEB_ENABLE_AUTOSEARCH           "enable-autosearch"
+#define EPHY_PREFS_WEB_ENABLE_MOUSE_GESTURES       "enable-mouse-gestures"
 
 static const char * const ephy_prefs_web_schema[] = {
   EPHY_PREFS_WEB_FONT_MIN_SIZE,
@@ -144,7 +145,8 @@ static const char * const ephy_prefs_web_schema[] = {
   EPHY_PREFS_WEB_ENABLE_SAFE_BROWSING,
   EPHY_PREFS_WEB_GSB_API_KEY,
   EPHY_PREFS_WEB_DEFAULT_ZOOM_LEVEL,
-  EPHY_PREFS_WEB_ENABLE_AUTOSEARCH
+  EPHY_PREFS_WEB_ENABLE_AUTOSEARCH,
+  EPHY_PREFS_WEB_ENABLE_MOUSE_GESTURES
 };
 
 #define EPHY_PREFS_SCHEMA                             "org.gnome.Epiphany"
diff --git a/src/ephy-mouse-gesture-controller.c b/src/ephy-mouse-gesture-controller.c
new file mode 100644
index 000000000..5cc286019
--- /dev/null
+++ b/src/ephy-mouse-gesture-controller.c
@@ -0,0 +1,321 @@
+/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ *  Copyright © 2018 Jan-Michael Brummer
+ *
+ *  This file is part of Epiphany.
+ *
+ *  Epiphany is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Epiphany 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Epiphany.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "ephy-embed.h"
+#include "ephy-mouse-gesture-controller.h"
+#include "ephy-prefs.h"
+#include "ephy-settings.h"
+#include "ephy-window.h"
+
+#include <math.h>
+#include <gtk/gtk.h>
+
+#define NUM_SEQUENCES 2
+
+typedef enum {
+  MOUSE_DIRECTION_UNKNOWN = 0,
+  MOUSE_DIRECTION_RIGHT,
+  MOUSE_DIRECTION_LEFT,
+  MOUSE_DIRECTION_DOWN,
+  MOUSE_DIRECTION_UP,
+} MouseDirection;
+
+struct _EphyMouseGestureController {
+  GObject parent_instance;
+
+  GtkEventController *controller;
+  EphyWindow *window;
+  WebKitWebView *web_view;
+
+  MouseDirection sequence[NUM_SEQUENCES];
+  MouseDirection direction;
+  gint sequence_pos;
+  gdouble last_x;
+  gdouble last_y;
+  gboolean gesture_active;
+};
+
+enum {
+  PROP_0,
+  PROP_WINDOW,
+  LAST_PROP
+};
+
+static GParamSpec *obj_properties[LAST_PROP];
+
+G_DEFINE_TYPE (EphyMouseGestureController, ephy_mouse_gesture_controller, G_TYPE_OBJECT)
+
+static void
+ephy_mouse_gesture_controller_motion_cb (GtkEventControllerMotion *controller,
+                                         gdouble                   x,
+                                         gdouble                   y,
+                                         gpointer                  user_data)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (user_data);
+  MouseDirection direction;
+  gdouble offset_x, offset_y;
+
+  if (!self->gesture_active || self->sequence_pos == NUM_SEQUENCES)
+    return;
+
+  if (isnan (self->last_x) || isnan (self->last_y)) {
+    self->last_x = x;
+    self->last_y = y;
+    return;
+  }
+
+  offset_x = x - self->last_x;
+  offset_y = y - self->last_y;
+
+  /* Try to guess direction */
+  if (fabs (offset_x) > fabs (offset_y) * 2) {
+    if (offset_x > 0)
+      direction = MOUSE_DIRECTION_RIGHT;
+    else
+      direction = MOUSE_DIRECTION_LEFT;
+  } else if (fabs (offset_y) > fabs (offset_x) * 2) {
+    if (offset_y > 0)
+      direction = MOUSE_DIRECTION_DOWN;
+    else
+      direction = MOUSE_DIRECTION_UP;
+  } else {
+    return;
+  }
+
+  self->last_x = x;
+  self->last_y = y;
+
+  if (self->direction == direction)
+    return;
+
+  self->sequence[self->sequence_pos++] = direction;
+
+  self->direction = direction;
+}
+
+static void
+ephy_mouse_gesture_controller_set_property (GObject      *object,
+                                            guint         prop_id,
+                                            const GValue *value,
+                                            GParamSpec   *pspec)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (object);
+
+  switch (prop_id) {
+    case PROP_WINDOW:
+      self->window = g_value_get_object (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+ephy_mouse_gesture_controller_get_property (GObject    *object,
+                                            guint       prop_id,
+                                            GValue     *value,
+                                            GParamSpec *pspec)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (object);
+
+  switch (prop_id) {
+    case PROP_WINDOW:
+      g_value_set_object (value, self->window);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+ephy_mouse_gesture_controller_reset (EphyMouseGestureController *self)
+{
+  self->direction = MOUSE_DIRECTION_UNKNOWN;
+  self->sequence_pos = 0;
+  self->last_x = NAN;
+  self->last_y = NAN;
+  self->gesture_active = FALSE;
+}
+
+static gboolean
+ephy_mouse_gesture_controller_button_press_cb (GtkWidget *widget,
+                                               GdkEvent  *event,
+                                               gpointer   user_data)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (user_data);
+  GdkEventButton *button_event = (GdkEventButton *)event;
+
+  if (button_event->button == GDK_BUTTON_MIDDLE)
+    self->gesture_active = TRUE;
+  else
+    self->gesture_active = FALSE;
+
+  return FALSE;
+}
+
+static void
+handle_gesture (gpointer user_data)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (user_data);
+  GActionGroup *action_group_toolbar = gtk_widget_get_action_group (GTK_WIDGET (self->window), "toolbar");
+  GActionGroup *action_group_win = gtk_widget_get_action_group (GTK_WIDGET (self->window), "win");
+  GActionGroup *action_group_tab = gtk_widget_get_action_group (GTK_WIDGET (self->window), "tab");
+  GAction *action;
+
+  switch (self->sequence_pos) {
+    case 1:
+      if (self->sequence[0] == MOUSE_DIRECTION_LEFT) {
+        /* Nav back */
+        action = g_action_map_lookup_action (G_ACTION_MAP (action_group_toolbar), "navigation-back");
+        g_action_activate (action, NULL);
+      } else if (self->sequence[0] == MOUSE_DIRECTION_RIGHT) {
+        /* Nav forward */
+        action = g_action_map_lookup_action (G_ACTION_MAP (action_group_toolbar), "navigation-forward");
+        g_action_activate (action, NULL);
+      } else if (self->sequence[0] == MOUSE_DIRECTION_DOWN) {
+        /* New tab */
+        action = g_action_map_lookup_action (G_ACTION_MAP (action_group_win), "new-tab");
+        g_action_activate (action, NULL);
+      }
+      break;
+    case 2:
+      if (self->sequence[0] == MOUSE_DIRECTION_DOWN && self->sequence[1] == MOUSE_DIRECTION_RIGHT) {
+        /* Close tab */
+        action = g_action_map_lookup_action (G_ACTION_MAP (action_group_tab), "close");
+        g_action_activate (action, NULL);
+      } else if (self->sequence[0] == MOUSE_DIRECTION_UP && self->sequence[1] == MOUSE_DIRECTION_DOWN) {
+        /* Reload tab */
+        action = g_action_map_lookup_action (G_ACTION_MAP (action_group_toolbar), "reload");
+        g_action_activate (action, NULL);
+      }
+      break;
+    default:
+      break;
+  }
+
+  ephy_mouse_gesture_controller_reset (self);
+}
+
+static gboolean
+ephy_mouse_gesture_controller_button_release_cb (GtkWidget *widget,
+                                                 GdkEvent  *event,
+                                                 gpointer   user_data)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (user_data);
+  GdkEventButton *button_event = (GdkEventButton *)event;
+
+  if (button_event->button == GDK_BUTTON_MIDDLE) {
+    if (self->gesture_active && g_settings_get_boolean (EPHY_SETTINGS_WEB, EPHY_PREFS_WEB_ENABLE_MOUSE_GESTURES))
+      handle_gesture (user_data);
+
+    self->gesture_active = FALSE;
+  }
+
+  return FALSE;
+}
+
+static void
+ephy_mouse_gesture_controller_init (EphyMouseGestureController *self)
+{
+}
+
+void
+ephy_mouse_gesture_controller_unset_web_view (EphyMouseGestureController *self)
+{
+  g_signal_handlers_disconnect_by_func (self->web_view,
+                                        G_CALLBACK (ephy_mouse_gesture_controller_button_press_cb),
+                                        self);
+  g_signal_handlers_disconnect_by_func (self->web_view,
+                                        G_CALLBACK (ephy_mouse_gesture_controller_button_release_cb),
+                                        self);
+}
+
+static void
+ephy_mouse_gesture_controller_dispose (GObject *object)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (object);
+
+  if (self->controller != NULL && self->window != NULL)
+    g_signal_handlers_disconnect_by_func (self->controller,
+                                          G_CALLBACK (ephy_mouse_gesture_controller_motion_cb),
+                                          self);
+  ephy_mouse_gesture_controller_unset_web_view (self);
+
+  g_clear_object (&self->controller);
+
+  G_OBJECT_CLASS (ephy_mouse_gesture_controller_parent_class)->dispose (object);
+}
+
+static void
+ephy_mouse_gesture_controller_constructed (GObject *object)
+{
+  EphyMouseGestureController *self = EPHY_MOUSE_GESTURE_CONTROLLER (object);
+
+  ephy_mouse_gesture_controller_reset (self);
+
+#if GTK_CHECK_VERSION (3, 24, 0)
+  self->controller = gtk_event_controller_motion_new (GTK_WIDGET (self->window));
+  g_signal_connect (self->controller, "motion", G_CALLBACK (ephy_mouse_gesture_controller_motion_cb), self);
+#endif
+}
+
+static void
+ephy_mouse_gesture_controller_class_init (EphyMouseGestureControllerClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = ephy_mouse_gesture_controller_dispose;
+  object_class->constructed = ephy_mouse_gesture_controller_constructed;
+
+  /* class creation */
+  object_class->set_property = ephy_mouse_gesture_controller_set_property;
+  object_class->get_property = ephy_mouse_gesture_controller_get_property;
+
+  obj_properties[PROP_WINDOW] =
+    g_param_spec_object ("window",
+                         "window",
+                         "window",
+                         EPHY_TYPE_WINDOW,
+                         G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, LAST_PROP, obj_properties);
+}
+
+EphyMouseGestureController *
+ephy_mouse_gesture_controller_new (EphyWindow *window)
+{
+  return g_object_new (EPHY_TYPE_MOUSE_GESTURE_CONTROLLER,
+                       "window", window,
+                       NULL);
+}
+
+void
+ephy_mouse_gesture_controller_set_web_view (EphyMouseGestureController *self,
+                                            WebKitWebView              *web_view)
+{
+  g_signal_connect (web_view, "button-press-event", G_CALLBACK (ephy_mouse_gesture_controller_button_press_cb), self);
+  g_signal_connect (web_view, "button-release-event", G_CALLBACK (ephy_mouse_gesture_controller_button_release_cb), self);
+
+  self->web_view = web_view;
+}
diff --git a/src/ephy-mouse-gesture-controller.h b/src/ephy-mouse-gesture-controller.h
new file mode 100644
index 000000000..06982a94e
--- /dev/null
+++ b/src/ephy-mouse-gesture-controller.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ *  Copyright © 2018 Jan-Michael Brummer
+ *
+ *  This file is part of Epiphany.
+ *
+ *  Epiphany is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Epiphany 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Epiphany.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "ephy-window.h"
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define EPHY_TYPE_MOUSE_GESTURE_CONTROLLER (ephy_mouse_gesture_controller_get_type ())
+
+G_DECLARE_FINAL_TYPE (EphyMouseGestureController, ephy_mouse_gesture_controller, EPHY, MOUSE_GESTURE_CONTROLLER, GObject);
+
+EphyMouseGestureController *ephy_mouse_gesture_controller_new (EphyWindow *window);
+
+void ephy_mouse_gesture_controller_set_web_view (EphyMouseGestureController *self,
+                                                 WebKitWebView              *web_view);
+void ephy_mouse_gesture_controller_unset_web_view (EphyMouseGestureController *self);
+
+
+G_END_DECLS
diff --git a/src/ephy-window.c b/src/ephy-window.c
index 91db4fae5..c128b9102 100644
--- a/src/ephy-window.c
+++ b/src/ephy-window.c
@@ -40,6 +40,7 @@
 #include "ephy-header-bar.h"
 #include "ephy-link.h"
 #include "ephy-location-entry.h"
+#include "ephy-mouse-gesture-controller.h"
 #include "ephy-notebook.h"
 #include "ephy-prefs.h"
 #include "ephy-security-popover.h"
@@ -152,6 +153,7 @@ struct _EphyWindow {
   guint idle_worker;
   EphyLocationController *location_controller;
   guint modified_forms_timeout_id;
+  EphyMouseGestureController *mouse_gesture_controller;
 
   gboolean show_fullscreen_header_bar;
 
@@ -2286,6 +2288,8 @@ ephy_window_connect_active_embed (EphyWindow *window)
                            G_CALLBACK (ephy_window_mouse_target_changed_cb),
                            window, 0);
 
+  ephy_mouse_gesture_controller_set_web_view (window->mouse_gesture_controller, web_view);
+
   g_object_notify (G_OBJECT (window), "active-child");
 }
 
@@ -2304,6 +2308,8 @@ ephy_window_disconnect_active_embed (EphyWindow *window)
 
   ephy_embed_detach_notification_container (window->active_embed);
 
+  ephy_mouse_gesture_controller_unset_web_view (window->mouse_gesture_controller);
+
   g_signal_handlers_disconnect_by_func (web_view,
                                         G_CALLBACK (progress_update),
                                         window);
@@ -2903,6 +2909,7 @@ ephy_window_dispose (GObject *object)
 
     g_clear_object (&window->bookmarks_manager);
     g_clear_object (&window->hit_test_result);
+    g_clear_object (&window->mouse_gesture_controller);
 
     g_clear_handle_id (&window->modified_forms_timeout_id, g_source_remove);
 
@@ -3440,6 +3447,8 @@ ephy_window_constructed (GObject *object)
                                           SENS_FLAG_CHROME, TRUE);
   }
 
+  window->mouse_gesture_controller = ephy_mouse_gesture_controller_new (window);
+
   ephy_window_set_chrome (window, chrome);
 }
 
diff --git a/src/meson.build b/src/meson.build
index 967ea1143..c346172ef 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -32,6 +32,7 @@ libephymain_sources = [
   'ephy-link.c',
   'ephy-location-controller.c',
   'ephy-lockdown.c',
+  'ephy-mouse-gesture-controller.c',
   'ephy-notebook.c',
   'ephy-search-engine-dialog.c',
   'ephy-session.c',