chrome/browser/ui/gtk/tabs/tab_gtk.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/gtk/tabs/tab_gtk.h"
   6
   7 #include <gdk/gdkkeysyms.h>
   8
   9 #include "base/bind.h"
  10 #include "base/debug/trace_event.h"
  11 #include "base/memory/singleton.h"
  12 #include "base/strings/utf_string_conversions.h"
  13 #include "chrome/app/chrome_command_ids.h"
  14 #include "chrome/browser/ui/gtk/accelerators_gtk.h"
  15 #include "chrome/browser/ui/gtk/gtk_input_event_box.h"
  16 #include "chrome/browser/ui/gtk/menu_gtk.h"
  17 #include "chrome/browser/ui/gtk/tabs/tab_strip_menu_controller.h"
  18 #include "chrome/browser/ui/tabs/tab_menu_model.h"
  19 #include "chrome/browser/ui/tabs/tab_resources.h"
  20 #include "grit/generated_resources.h"
  21 #include "grit/theme_resources.h"
  22 #include "ui/base/dragdrop/gtk_dnd_util.h"
  23 #include "ui/base/gtk/scoped_region.h"
  24 #include "ui/gfx/path.h"
  25
  26 using content::WebContents;
  27
  28 namespace {
  29
  30 // Returns the width of the title for the current font, in pixels.
  31 int GetTitleWidth(gfx::Font* font, base::string16 title) {
  32   DCHECK(font);
  33   if (title.empty())
  34     return 0;
  35
  36   return font->GetStringWidth(title);
  37 }
  38
  39 }  // namespace
  40
  41 class TabGtk::TabGtkObserverHelper {
  42  public:
  43   explicit TabGtkObserverHelper(TabGtk* tab)
  44       : tab_(tab) {
  45     base::MessageLoopForUI::current()->AddObserver(tab_);
  46   }
  47
  48   ~TabGtkObserverHelper() {
  49     base::MessageLoopForUI::current()->RemoveObserver(tab_);
  50   }
  51
  52  private:
  53   TabGtk* tab_;
  54
  55   DISALLOW_COPY_AND_ASSIGN(TabGtkObserverHelper);
  56 };
  57
  58 ///////////////////////////////////////////////////////////////////////////////
  59 // TabGtk, public:
  60
  61 TabGtk::TabGtk(TabDelegate* delegate)
  62     : TabRendererGtk(delegate->GetThemeProvider()),
  63       delegate_(delegate),
  64       closing_(false),
  65       dragging_(false),
  66       last_mouse_down_(NULL),
  67       drag_widget_(NULL),
  68       title_width_(0),
  69       destroy_factory_(this),
  70       drag_end_factory_(this) {
  71   event_box_ = gtk_input_event_box_new();
  72   g_signal_connect(event_box_, "button-press-event",
  73                    G_CALLBACK(OnButtonPressEventThunk), this);
  74   g_signal_connect(event_box_, "button-release-event",
  75                    G_CALLBACK(OnButtonReleaseEventThunk), this);
  76   g_signal_connect(event_box_, "enter-notify-event",
  77                    G_CALLBACK(OnEnterNotifyEventThunk), this);
  78   g_signal_connect(event_box_, "leave-notify-event",
  79                    G_CALLBACK(OnLeaveNotifyEventThunk), this);
  80   gtk_widget_add_events(event_box_,
  81         GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
  82         GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK);
  83   gtk_container_add(GTK_CONTAINER(event_box_), TabRendererGtk::widget());
  84   gtk_widget_show_all(event_box_);
  85 }
  86
  87 TabGtk::~TabGtk() {
  88   if (drag_widget_) {
  89     // Shadow the drag grab so the grab terminates. We could do this using any
  90     // widget, |drag_widget_| is just convenient.
  91     gtk_grab_add(drag_widget_);
  92     gtk_grab_remove(drag_widget_);
  93     DestroyDragWidget();
  94   }
  95
  96   if (menu_controller_.get()) {
  97     // The menu is showing. Close the menu.
  98     menu_controller_->Cancel();
  99
 100     // Invoke this so that we hide the highlight.
 101     ContextMenuClosed();
 102   }
 103 }
 104
 105 void TabGtk::Raise() const {
 106   UNSHIPPED_TRACE_EVENT0("ui::gtk", "TabGtk::Raise");
 107
 108   GdkWindow* window = gtk_input_event_box_get_window(
 109       GTK_INPUT_EVENT_BOX(event_box_));
 110   gdk_window_raise(window);
 111   TabRendererGtk::Raise();
 112 }
 113
 114 gboolean TabGtk::OnButtonPressEvent(GtkWidget* widget, GdkEventButton* event) {
 115   // Every button press ensures either a button-release-event or a drag-fail
 116   // signal for |widget|.
 117   if (event->button == 1 && event->type == GDK_BUTTON_PRESS) {
 118     // Store whether or not we were selected just now... we only want to be
 119     // able to drag foreground tabs, so we don't start dragging the tab if
 120     // it was in the background.
 121     if (!IsActive()) {
 122       if (event->state & GDK_CONTROL_MASK)
 123         delegate_->ToggleTabSelection(this);
 124       else if (event->state & GDK_SHIFT_MASK)
 125         delegate_->ExtendTabSelection(this);
 126       else
 127         delegate_->ActivateTab(this);
 128     }
 129     // Hook into the message loop to handle dragging.
 130     observer_.reset(new TabGtkObserverHelper(this));
 131
 132     // Store the button press event, used to initiate a drag.
 133     last_mouse_down_ = gdk_event_copy(reinterpret_cast<GdkEvent*>(event));
 134   } else if (event->button == 3) {
 135     // Only show the context menu if the left mouse button isn't down (i.e.,
 136     // the user might want to drag instead).
 137     if (!last_mouse_down_) {
 138       menu_controller_.reset(delegate()->GetTabStripMenuControllerForTab(this));
 139       menu_controller_->RunMenu(gfx::Point(event->x_root, event->y_root),
 140                                 event->time);
 141     }
 142   }
 143
 144   return TRUE;
 145 }
 146
 147 gboolean TabGtk::OnButtonReleaseEvent(GtkWidget* widget,
 148                                       GdkEventButton* event) {
 149   if (event->button == 1) {
 150     if (IsActive() && !(event->state & (GDK_SHIFT_MASK | GDK_CONTROL_MASK))) {
 151       delegate_->ActivateTab(this);
 152     }
 153     observer_.reset();
 154
 155     if (last_mouse_down_) {
 156       gdk_event_free(last_mouse_down_);
 157       last_mouse_down_ = NULL;
 158     }
 159   }
 160
 161   GtkAllocation allocation;
 162   gtk_widget_get_allocation(widget, &allocation);
 163
 164   // Middle mouse up means close the tab, but only if the mouse is over it
 165   // (like a button).
 166   if (event->button == 2 &&
 167       event->x >= 0 && event->y >= 0 &&
 168       event->x < allocation.width &&
 169       event->y < allocation.height) {
 170     // If the user is currently holding the left mouse button down but hasn't
 171     // moved the mouse yet, a drag hasn't started yet.  In that case, clean up
 172     // some state before closing the tab to avoid a crash.  Once the drag has
 173     // started, we don't get the middle mouse click here.
 174     if (last_mouse_down_) {
 175       DCHECK(!drag_widget_);
 176       observer_.reset();
 177       gdk_event_free(last_mouse_down_);
 178       last_mouse_down_ = NULL;
 179     }
 180     delegate_->CloseTab(this);
 181   }
 182
 183   return TRUE;
 184 }
 185
 186 gboolean TabGtk::OnDragFailed(GtkWidget* widget, GdkDragContext* context,
 187                               GtkDragResult result) {
 188   bool canceled = (result == GTK_DRAG_RESULT_USER_CANCELLED);
 189   EndDrag(canceled);
 190   return TRUE;
 191 }
 192
 193 gboolean TabGtk::OnDragButtonReleased(GtkWidget* widget,
 194                                       GdkEventButton* button) {
 195   // We always get this event when gtk is releasing the grab and ending the
 196   // drag.  However, if the user ended the drag with space or enter, we don't
 197   // get a follow up event to tell us the drag has finished (either a
 198   // drag-failed or a drag-end).  So we post a task to manually end the drag.
 199   // If GTK+ does send the drag-failed or drag-end event, we cancel the task.
 200   base::MessageLoop::current()->PostTask(
 201       FROM_HERE,
 202       base::Bind(&TabGtk::EndDrag, drag_end_factory_.GetWeakPtr(), false));
 203   return TRUE;
 204 }
 205
 206 void TabGtk::OnDragBegin(GtkWidget* widget, GdkDragContext* context) {
 207   GdkPixbuf* pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, 1, 1);
 208   gdk_pixbuf_fill(pixbuf, 0);
 209   gtk_drag_set_icon_pixbuf(context, pixbuf, 0, 0);
 210   g_object_unref(pixbuf);
 211 }
 212
 213 ///////////////////////////////////////////////////////////////////////////////
 214 // TabGtk, MessageLoop::Observer implementation:
 215
 216 void TabGtk::WillProcessEvent(GdkEvent* event) {
 217   // Nothing to do.
 218 }
 219
 220 void TabGtk::DidProcessEvent(GdkEvent* event) {
 221   if (!(event->type == GDK_MOTION_NOTIFY || event->type == GDK_LEAVE_NOTIFY ||
 222         event->type == GDK_ENTER_NOTIFY)) {
 223     return;
 224   }
 225
 226   if (drag_widget_) {
 227     delegate_->ContinueDrag(NULL);
 228     return;
 229   }
 230
 231   gint old_x = static_cast<gint>(last_mouse_down_->button.x_root);
 232   gint old_y = static_cast<gint>(last_mouse_down_->button.y_root);
 233   gdouble new_x;
 234   gdouble new_y;
 235   gdk_event_get_root_coords(event, &new_x, &new_y);
 236
 237   if (gtk_drag_check_threshold(widget(), old_x, old_y,
 238       static_cast<gint>(new_x), static_cast<gint>(new_y))) {
 239     StartDragging(gfx::Point(
 240         static_cast<int>(last_mouse_down_->button.x),
 241         static_cast<int>(last_mouse_down_->button.y)));
 242   }
 243 }
 244
 245 ///////////////////////////////////////////////////////////////////////////////
 246 // TabGtk, TabRendererGtk overrides:
 247
 248 bool TabGtk::IsActive() const {
 249   return delegate_->IsTabActive(this);
 250 }
 251
 252 bool TabGtk::IsSelected() const {
 253   return delegate_->IsTabSelected(this);
 254 }
 255
 256 bool TabGtk::IsVisible() const {
 257   return gtk_widget_get_visible(event_box_);
 258 }
 259
 260 void TabGtk::SetVisible(bool visible) const {
 261   gtk_widget_set_visible(event_box_, visible);
 262 }
 263
 264 void TabGtk::CloseButtonClicked() {
 265   delegate_->CloseTab(this);
 266 }
 267
 268 void TabGtk::UpdateData(WebContents* contents, bool app, bool loading_only) {
 269   TabRendererGtk::UpdateData(contents, app, loading_only);
 270   // Cache the title width so we don't recalculate it every time the tab is
 271   // resized.
 272   title_width_ = GetTitleWidth(title_font(), GetTitle());
 273   UpdateTooltipState();
 274 }
 275
 276 void TabGtk::SetBounds(const gfx::Rect& bounds) {
 277   TabRendererGtk::SetBounds(bounds);
 278
 279   if (gtk_input_event_box_get_window(GTK_INPUT_EVENT_BOX(event_box_))) {
 280     gfx::Path mask;
 281     TabResources::GetHitTestMask(bounds.width(), bounds.height(), false, &mask);
 282     ui::ScopedRegion region(mask.CreateNativeRegion());
 283     gdk_window_input_shape_combine_region(
 284         gtk_input_event_box_get_window(GTK_INPUT_EVENT_BOX(event_box_)),
 285         region.Get(),
 286         0, 0);
 287   }
 288
 289   UpdateTooltipState();
 290 }
 291
 292 ///////////////////////////////////////////////////////////////////////////////
 293 // TabGtk, private:
 294
 295 void TabGtk::ContextMenuClosed() {
 296   delegate()->StopAllHighlighting();
 297   menu_controller_.reset();
 298 }
 299
 300 void TabGtk::UpdateTooltipState() {
 301   // Note: This method can be called several times per second for various
 302   // reasons (e.g., navigation/loading state changes, tab media indicator
 303   // updates, and so on).  However, we must avoid calling the
 304   // gtk_widget_set_XXX() methods if there is no actual change in state.
 305   // Otherwise, GTK will continuously re-hide *all* tooltips throughout the
 306   // browser in response!  http://crbug.com/333002
 307
 308   // Only show the tooltip if the title is truncated.
 309   if (title_width_ > title_bounds().width()) {
 310     const std::string utf8_title = base::UTF16ToUTF8(GetTitle());
 311     if (gtk_widget_get_has_tooltip(widget())) {
 312       gchar* const current_tooltip = gtk_widget_get_tooltip_text(widget());
 313       if (current_tooltip) {
 314         const bool title_unchanged = (utf8_title == current_tooltip);
 315         g_free(current_tooltip);
 316         if (title_unchanged)
 317           return;
 318       }
 319     }
 320     gtk_widget_set_tooltip_text(widget(), utf8_title.c_str());
 321   } else {
 322     if (gtk_widget_get_has_tooltip(widget()))
 323       gtk_widget_set_has_tooltip(widget(), FALSE);
 324   }
 325 }
 326
 327 void TabGtk::CreateDragWidget() {
 328   DCHECK(!drag_widget_);
 329   drag_widget_ = gtk_invisible_new();
 330   g_signal_connect(drag_widget_, "drag-failed",
 331                    G_CALLBACK(OnDragFailedThunk), this);
 332   g_signal_connect(drag_widget_, "button-release-event",
 333                    G_CALLBACK(OnDragButtonReleasedThunk), this);
 334   g_signal_connect_after(drag_widget_, "drag-begin",
 335                          G_CALLBACK(OnDragBeginThunk), this);
 336 }
 337
 338 void TabGtk::DestroyDragWidget() {
 339   if (drag_widget_) {
 340     gtk_widget_destroy(drag_widget_);
 341     drag_widget_ = NULL;
 342   }
 343 }
 344
 345 void TabGtk::StartDragging(gfx::Point drag_offset) {
 346   // If the drag is processed after the selection change it's possible
 347   // that the tab has been deselected, in which case we don't want to drag.
 348   if (!IsSelected())
 349     return;
 350
 351   CreateDragWidget();
 352
 353   GtkTargetList* list = ui::GetTargetListFromCodeMask(ui::CHROME_TAB);
 354   gtk_drag_begin(drag_widget_, list, GDK_ACTION_MOVE,
 355                  1,  // Drags are always initiated by the left button.
 356                  last_mouse_down_);
 357   // gtk_drag_begin adds a reference to list, so unref it here.
 358   gtk_target_list_unref(list);
 359   delegate_->MaybeStartDrag(this, drag_offset);
 360 }
 361
 362 void TabGtk::EndDrag(bool canceled) {
 363   // Make sure we only run EndDrag once by canceling any tasks that want
 364   // to call EndDrag.
 365   drag_end_factory_.InvalidateWeakPtrs();
 366
 367   // We must let gtk clean up after we handle the drag operation, otherwise
 368   // there will be outstanding references to the drag widget when we try to
 369   // destroy it.
 370   base::MessageLoop::current()->PostTask(
 371       FROM_HERE,
 372       base::Bind(&TabGtk::DestroyDragWidget, destroy_factory_.GetWeakPtr()));
 373
 374   if (last_mouse_down_) {
 375     gdk_event_free(last_mouse_down_);
 376     last_mouse_down_ = NULL;
 377   }
 378
 379   // Notify the drag helper that we're done with any potential drag operations.
 380   // Clean up the drag helper, which is re-created on the next mouse press.
 381   delegate_->EndDrag(canceled);
 382
 383   observer_.reset();
 384 }