// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/gtk/tabs/tab_gtk.h"

#include <gdk/gdkkeysyms.h>

#include "app/gtk_dnd_util.h"
#include "app/gfx/path.h"
#include "app/l10n_util.h"
#include "app/resource_bundle.h"
#include "chrome/browser/gtk/menu_gtk.h"
#include "chrome/browser/gtk/standard_menus.h"
#include "grit/generated_resources.h"
#include "grit/theme_resources.h"

namespace {

void SetEmptyDragIcon(GtkWidget* widget) {
  GdkPixbuf* pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, 1, 1);
  gtk_drag_source_set_icon_pixbuf(widget, pixbuf);
  g_object_unref(pixbuf);
}

// Returns the width of the title for the current font, in pixels.
int GetTitleWidth(gfx::Font* font, std::wstring title) {
  DCHECK(font);
  if (title.empty())
    return 0;

  return font->GetStringWidth(title);
}

}  // namespace

class TabGtk::ContextMenuController : public MenuGtk::Delegate {
 public:
  explicit ContextMenuController(TabGtk* tab)
      : tab_(tab) {
    static const MenuCreateMaterial context_menu_blueprint[] = {
        { MENU_NORMAL, TabStripModel::CommandNewTab, IDS_TAB_CXMENU_NEWTAB,
            0, NULL, GDK_t, GDK_CONTROL_MASK, true },
        { MENU_SEPARATOR },
        { MENU_NORMAL, TabStripModel::CommandReload, IDS_TAB_CXMENU_RELOAD,
            0, NULL, GDK_r, GDK_CONTROL_MASK, true },
        { MENU_NORMAL, TabStripModel::CommandDuplicate,
            IDS_TAB_CXMENU_DUPLICATE },
        { MENU_SEPARATOR },
        { MENU_NORMAL, TabStripModel::CommandCloseTab, IDS_TAB_CXMENU_CLOSETAB,
            0, NULL, GDK_w, GDK_CONTROL_MASK, true },
        { MENU_NORMAL, TabStripModel::CommandCloseOtherTabs,
          IDS_TAB_CXMENU_CLOSEOTHERTABS },
        { MENU_NORMAL, TabStripModel::CommandCloseTabsToRight,
            IDS_TAB_CXMENU_CLOSETABSTORIGHT },
        { MENU_NORMAL, TabStripModel::CommandCloseTabsOpenedBy,
            IDS_TAB_CXMENU_CLOSETABSOPENEDBY },
        { MENU_NORMAL, TabStripModel::CommandRestoreTab, IDS_RESTORE_TAB,
            0, NULL, GDK_t, GDK_CONTROL_MASK | GDK_SHIFT_MASK, true },
        { MENU_SEPARATOR },
        { MENU_CHECKBOX, TabStripModel::CommandTogglePinned,
            IDS_TAB_CXMENU_PIN_TAB },
        { MENU_END },
    };

    menu_.reset(new MenuGtk(this, context_menu_blueprint, NULL));
  }

  virtual ~ContextMenuController() {}

  void RunMenu() {
    menu_->PopupAsContext(gtk_get_current_event_time());
  }

  void Cancel() {
    tab_ = NULL;
    menu_->Cancel();
  }

 private:
  // MenuGtk::Delegate implementation:
  virtual bool IsCommandEnabled(int command_id) const {
    if (!tab_)
      return false;

    return tab_->delegate()->IsCommandEnabledForTab(
        static_cast<TabStripModel::ContextMenuCommand>(command_id), tab_);
  }

  virtual bool IsItemChecked(int command_id) const {
    if (!tab_ || command_id != TabStripModel::CommandTogglePinned)
      return false;
    return tab_->is_pinned();
  }

  virtual void ExecuteCommand(int command_id) {
    if (!tab_)
      return;

    tab_->delegate()->ExecuteCommandForTab(
        static_cast<TabStripModel::ContextMenuCommand>(command_id), tab_);
  }

  // The context menu.
  scoped_ptr<MenuGtk> menu_;

  // The Tab the context menu was brought up for. Set to NULL when the menu
  // is canceled.
  TabGtk* tab_;

  DISALLOW_COPY_AND_ASSIGN(ContextMenuController);
};

///////////////////////////////////////////////////////////////////////////////
// TabGtk, public:

TabGtk::TabGtk(TabDelegate* delegate)
    : TabRendererGtk(delegate->GetThemeProvider()),
      delegate_(delegate),
      closing_(false),
      last_mouse_down_(NULL),
      drag_widget_(NULL),
      title_width_(0),
      ALLOW_THIS_IN_INITIALIZER_LIST(destroy_factory_(this)) {
  event_box_ = gtk_event_box_new();
  gtk_event_box_set_visible_window(GTK_EVENT_BOX(event_box_), FALSE);
  g_signal_connect(G_OBJECT(event_box_), "button-press-event",
                   G_CALLBACK(OnButtonPressEvent), this);
  g_signal_connect(G_OBJECT(event_box_), "button-release-event",
                   G_CALLBACK(OnButtonReleaseEvent), this);
  g_signal_connect(G_OBJECT(event_box_), "enter-notify-event",
                   G_CALLBACK(OnEnterNotifyEvent), this);
  g_signal_connect(G_OBJECT(event_box_), "leave-notify-event",
                   G_CALLBACK(OnLeaveNotifyEvent), this);
  gtk_widget_add_events(event_box_,
        GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
        GDK_LEAVE_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK);
  gtk_container_add(GTK_CONTAINER(event_box_), TabRendererGtk::widget());
  gtk_widget_show_all(event_box_);
}

TabGtk::~TabGtk() {
  if (menu_controller_.get()) {
    // The menu is showing. Close the menu.
    menu_controller_->Cancel();

    // Invoke this so that we hide the highlight.
    ContextMenuClosed();
  }
}

// static
gboolean TabGtk::OnButtonPressEvent(GtkWidget* widget, GdkEventButton* event,
                                    TabGtk* tab) {
  // Every button press ensures either a button-release-event or a drag-fail
  // signal for |widget|.
  if (event->button == 1 && event->type == GDK_BUTTON_PRESS) {
    // Store whether or not we were selected just now... we only want to be
    // able to drag foreground tabs, so we don't start dragging the tab if
    // it was in the background.
    bool just_selected = !tab->IsSelected();
    if (just_selected) {
      tab->delegate_->SelectTab(tab);
    }

    // Hook into the message loop to handle dragging.
    MessageLoopForUI::current()->AddObserver(tab);

    // Store the button press event, used to initiate a drag.
    tab->last_mouse_down_ = gdk_event_copy(reinterpret_cast<GdkEvent*>(event));
  } else if (event->button == 3) {
    tab->ShowContextMenu();
  }

  return TRUE;
}

// static
gboolean TabGtk::OnButtonReleaseEvent(GtkWidget* widget, GdkEventButton* event,
                                      TabGtk* tab) {
  if (event->button == 1) {
    MessageLoopForUI::current()->RemoveObserver(tab);

    if (tab->last_mouse_down_) {
      gdk_event_free(tab->last_mouse_down_);
      tab->last_mouse_down_ = NULL;
    }
  }

  // Middle mouse up means close the tab, but only if the mouse is over it
  // (like a button).
  if (event->button == 2 &&
      event->x >= 0 && event->y >= 0 &&
      event->x < widget->allocation.width &&
      event->y < widget->allocation.height) {
    tab->delegate_->CloseTab(tab);
  }

  return TRUE;
}

// static
gboolean TabGtk::OnDragFailed(GtkWidget* widget, GdkDragContext* context,
                              GtkDragResult result,
                              TabGtk* tab) {
  bool canceled = (result == GTK_DRAG_RESULT_USER_CANCELLED);
  tab->EndDrag(canceled);
  return TRUE;
}

///////////////////////////////////////////////////////////////////////////////
// TabGtk, MessageLoop::Observer implementation:

void TabGtk::WillProcessEvent(GdkEvent* event) {
  // Nothing to do.
}

void TabGtk::DidProcessEvent(GdkEvent* event) {
  if (event->type != GDK_MOTION_NOTIFY)
    return;

  if (drag_widget_) {
    delegate_->ContinueDrag(NULL);
    return;
  }

  GdkEventMotion* motion = reinterpret_cast<GdkEventMotion*>(event);
  GdkEventButton* button = reinterpret_cast<GdkEventButton*>(last_mouse_down_);
  bool dragging = gtk_drag_check_threshold(widget(),
                                           button->x, button->y,
                                           motion->x, motion->y);
  if (dragging)
    StartDragging(gfx::Point(button->x, button->y));
}

///////////////////////////////////////////////////////////////////////////////
// TabGtk, TabRendererGtk overrides:

bool TabGtk::IsSelected() const {
  return delegate_->IsTabSelected(this);
}

bool TabGtk::IsVisible() const {
  return GTK_WIDGET_FLAGS(event_box_) & GTK_VISIBLE;
}

void TabGtk::SetVisible(bool visible) const {
  if (visible) {
    gtk_widget_show(event_box_);
  } else {
    gtk_widget_hide(event_box_);
  }
}

void TabGtk::CloseButtonClicked() {
  delegate_->CloseTab(this);
}

void TabGtk::UpdateData(TabContents* contents, bool loading_only) {
  TabRendererGtk::UpdateData(contents, loading_only);
  // Cache the title width so we don't recalculate it every time the tab is
  // resized.
  title_width_ = GetTitleWidth(title_font(), GetTitle());
  UpdateTooltipState();
}

void TabGtk::SetBounds(const gfx::Rect& bounds) {
  TabRendererGtk::SetBounds(bounds);
  UpdateTooltipState();
}

///////////////////////////////////////////////////////////////////////////////
// TabGtk, private:

void TabGtk::ShowContextMenu() {
  if (!menu_controller_.get())
    menu_controller_.reset(new ContextMenuController(this));

  menu_controller_->RunMenu();
}

void TabGtk::ContextMenuClosed() {
  delegate()->StopAllHighlighting();
  menu_controller_.reset();
}

void TabGtk::UpdateTooltipState() {
  // Only show the tooltip if the title is truncated.
  if (title_width_ > title_bounds().width()) {
    gtk_widget_set_tooltip_text(widget(), WideToUTF8(GetTitle()).c_str());
  } else {
    gtk_widget_set_has_tooltip(widget(), FALSE);
  }
}

void TabGtk::CreateDragWidget() {
  drag_widget_ = gtk_invisible_new();
  g_signal_connect(drag_widget_, "drag-failed",
                   G_CALLBACK(OnDragFailed), this);
}

void TabGtk::DestroyDragWidget() {
  if (drag_widget_) {
    gtk_widget_destroy(drag_widget_);
    drag_widget_ = NULL;
  }
}

void TabGtk::StartDragging(gfx::Point drag_offset) {
  CreateDragWidget();

  GtkTargetList* list = GtkDndUtil::GetTargetListFromCodeMask(
      GtkDndUtil::CHROME_TAB);
  gtk_drag_begin(drag_widget_, list, GDK_ACTION_COPY,
                 1,  // Drags are always initiated by the left button.
                 last_mouse_down_);

  delegate_->MaybeStartDrag(this, drag_offset);
}

void TabGtk::EndDrag(bool canceled) {
  // We must let gtk clean up after we handle the drag operation, otherwise
  // there will be outstanding references to the drag widget when we try to
  // destroy it.
  MessageLoop::current()->PostTask(FROM_HERE,
      destroy_factory_.NewRunnableMethod(&TabGtk::DestroyDragWidget));

  if (last_mouse_down_) {
    gdk_event_free(last_mouse_down_);
    last_mouse_down_ = NULL;
  }

  // Notify the drag helper that we're done with any potential drag operations.
  // Clean up the drag helper, which is re-created on the next mouse press.
  delegate_->EndDrag(canceled);

  MessageLoopForUI::current()->RemoveObserver(this);
}