layout/printing/nsPrintPreviewListener.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is the Mozilla browser.
  17  *
  18  * The Initial Developer of the Original Code is
  19  * Netscape Communications, Inc.
  20  * Portions created by the Initial Developer are Copyright (C) 1999
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *   Mats Palmgren <mats.palmgren@bredband.net>
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either of the GNU General Public License Version 2 or later (the "GPL"),
  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
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  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #include "nsPrintPreviewListener.h"
  41 #include "nsIContent.h"
  42 #include "nsIDOMKeyEvent.h"
  43 #include "nsIDOMNSEvent.h"
  44 #include "nsIDocument.h"
  45 #include "nsIPresShell.h"
  46 #include "nsIDocShell.h"
  47 #include "nsPresContext.h"
  48 #include "nsIEventStateManager.h"
  49 #include "nsLiteralString.h"
  50
  51 NS_IMPL_ISUPPORTS1(nsPrintPreviewListener, nsIDOMEventListener)
  52
  53
  54 //
  55 // nsPrintPreviewListener ctor
  56 //
  57 nsPrintPreviewListener::nsPrintPreviewListener (nsIDOMEventTarget* aTarget)
  58   : mEventTarget(aTarget)
  59 {
  60   NS_ADDREF_THIS();
  61 } // ctor
  62
  63
  64 //-------------------------------------------------------
  65 //
  66 // AddListeners
  67 //
  68 // Subscribe to the events that will allow us to track various events.
  69 //
  70 nsresult
  71 nsPrintPreviewListener::AddListeners()
  72 {
  73   if (mEventTarget) {
  74     mEventTarget->AddEventListener(NS_LITERAL_STRING("click"), this, true);
  75     mEventTarget->AddEventListener(NS_LITERAL_STRING("contextmenu"), this, true);
  76     mEventTarget->AddEventListener(NS_LITERAL_STRING("keydown"), this, true);
  77     mEventTarget->AddEventListener(NS_LITERAL_STRING("keypress"), this, true);
  78     mEventTarget->AddEventListener(NS_LITERAL_STRING("keyup"), this, true);
  79     mEventTarget->AddEventListener(NS_LITERAL_STRING("mousedown"), this, true);
  80     mEventTarget->AddEventListener(NS_LITERAL_STRING("mousemove"), this, true);
  81     mEventTarget->AddEventListener(NS_LITERAL_STRING("mouseout"), this, true);
  82     mEventTarget->AddEventListener(NS_LITERAL_STRING("mouseover"), this, true);
  83     mEventTarget->AddEventListener(NS_LITERAL_STRING("mouseup"), this, true);
  84   }
  85
  86   return NS_OK;
  87 }
  88
  89
  90 //-------------------------------------------------------
  91 //
  92 // RemoveListeners
  93 //
  94 // Unsubscribe from all the various events that we were listening to.
  95 //
  96 nsresult
  97 nsPrintPreviewListener::RemoveListeners()
  98 {
  99   if (mEventTarget) {
 100     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("click"), this, true);
 101     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("contextmenu"), this, true);
 102     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("keydown"), this, true);
 103     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("keypress"), this, true);
 104     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("keyup"), this, true);
 105     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mousedown"), this, true);
 106     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mousemove"), this, true);
 107     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mouseout"), this, true);
 108     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mouseover"), this, true);
 109     mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mouseup"), this, true);
 110   }
 111
 112   return NS_OK;
 113 }
 114
 115 //-------------------------------------------------------
 116 //
 117 // GetActionForEvent
 118 //
 119 // Helper function to let certain key events through
 120 //
 121 enum eEventAction {
 122   eEventAction_Tab,       eEventAction_ShiftTab,
 123   eEventAction_Propagate, eEventAction_Suppress
 124 };
 125
 126 static eEventAction
 127 GetActionForEvent(nsIDOMEvent* aEvent)
 128 {
 129   static const PRUint32 kOKKeyCodes[] = {
 130     nsIDOMKeyEvent::DOM_VK_PAGE_UP, nsIDOMKeyEvent::DOM_VK_PAGE_DOWN,
 131     nsIDOMKeyEvent::DOM_VK_UP,      nsIDOMKeyEvent::DOM_VK_DOWN,
 132     nsIDOMKeyEvent::DOM_VK_HOME,    nsIDOMKeyEvent::DOM_VK_END
 133   };
 134
 135   nsCOMPtr<nsIDOMKeyEvent> keyEvent(do_QueryInterface(aEvent));
 136   if (keyEvent) {
 137     PRBool b;
 138     keyEvent->GetAltKey(&b);
 139     if (b) return eEventAction_Suppress;
 140     keyEvent->GetCtrlKey(&b);
 141     if (b) return eEventAction_Suppress;
 142
 143     keyEvent->GetShiftKey(&b);
 144
 145     PRUint32 keyCode;
 146     keyEvent->GetKeyCode(&keyCode);
 147     if (keyCode == nsIDOMKeyEvent::DOM_VK_TAB)
 148       return b ? eEventAction_ShiftTab : eEventAction_Tab;
 149
 150     PRUint32 charCode;
 151     keyEvent->GetCharCode(&charCode);
 152     if (charCode == ' ' || keyCode == nsIDOMKeyEvent::DOM_VK_SPACE)
 153       return eEventAction_Propagate;
 154
 155     if (b) return eEventAction_Suppress;
 156
 157     for (PRUint32 i = 0; i < sizeof(kOKKeyCodes)/sizeof(kOKKeyCodes[0]); ++i) {
 158       if (keyCode == kOKKeyCodes[i]) {
 159         return eEventAction_Propagate;
 160       }
 161     }
 162   }
 163   return eEventAction_Suppress;
 164 }
 165
 166 NS_IMETHODIMP
 167 nsPrintPreviewListener::HandleEvent(nsIDOMEvent* aEvent)
 168 {
 169   nsCOMPtr<nsIDOMEventTarget> target;
 170   nsCOMPtr<nsIDOMNSEvent> nsEvent = do_QueryInterface(aEvent);
 171   if (nsEvent)
 172     nsEvent->GetOriginalTarget(getter_AddRefs(target));
 173   nsCOMPtr<nsIContent> content(do_QueryInterface(target));
 174   if (content && !content->IsNodeOfType(nsINode::eXUL)) {
 175     eEventAction action = ::GetActionForEvent(aEvent);
 176     switch (action) {
 177       case eEventAction_Tab:
 178       case eEventAction_ShiftTab:
 179       {
 180         nsAutoString eventString;
 181         aEvent->GetType(eventString);
 182         if (eventString == NS_LITERAL_STRING("keydown")) {
 183           // Handle tabbing explicitly here since we don't want focus ending up
 184           // inside the content document, bug 244128.
 185           nsIDocument* doc = content->GetCurrentDoc();
 186           NS_ASSERTION(doc, "no document");
 187
 188           nsIDocument* parentDoc = doc->GetParentDocument();
 189           NS_ASSERTION(parentDoc, "no parent document");
 190           nsIEventStateManager* esm =
 191             parentDoc->GetPrimaryShell()->GetPresContext()->EventStateManager();
 192           if (esm) {
 193             esm->SetContentState(nsnull, NS_EVENT_STATE_FOCUS);
 194             PRBool forward = (action == eEventAction_Tab);
 195             esm->ShiftFocus(forward,
 196                             forward ? nsnull : parentDoc->FindContentForSubDocument(doc));
 197           }
 198         }
 199       }
 200       // fall-through
 201       case eEventAction_Suppress:
 202         aEvent->StopPropagation();
 203         aEvent->PreventDefault();
 204         break;
 205       case eEventAction_Propagate:
 206         // intentionally empty
 207         break;
 208     }
 209   }
 210   return NS_OK;
 211 }