The Tor Browser: widget/windows/TaskbarTabPreview.cpp@ac0c01689b40 (annotated)

widget/windows/TaskbarTabPreview.cpp@ac0c01689b40 (annotated)

widget/windows/TaskbarTabPreview.cpp

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* vim: se cin sw=2 ts=2 et : */
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "TaskbarTabPreview.h"
 #include "nsWindowGfx.h"
 #include "nsUXThemeData.h"
 #include "WinUtils.h"
 #include <nsITaskbarPreviewController.h>
 #define TASKBARPREVIEW_HWNDID L"TaskbarTabPreviewHwnd"
 namespace mozilla {
 namespace widget {
 NS_IMPL_ISUPPORTS(TaskbarTabPreview, nsITaskbarTabPreview)
 const wchar_t *const kWindowClass = L"MozillaTaskbarPreviewClass";
 TaskbarTabPreview::TaskbarTabPreview(ITaskbarList4 *aTaskbar, nsITaskbarPreviewController *aController, HWND aHWND, nsIDocShell *aShell)
   : TaskbarPreview(aTaskbar, aController, aHWND, aShell),
     mProxyWindow(nullptr),
     mIcon(nullptr),
     mRegistered(false)
 {
   WindowHook &hook = GetWindowHook();
   hook.AddMonitor(WM_WINDOWPOSCHANGED, MainWindowHook, this);
 }
 TaskbarTabPreview::~TaskbarTabPreview() {
   if (mIcon) {
     ::DestroyIcon(mIcon);
     mIcon = nullptr;
   }
   // We need to ensure that proxy window disappears or else Bad Things happen.
   if (mProxyWindow)
     Disable();
   NS_ASSERTION(!mProxyWindow, "Taskbar proxy window was not destroyed!");
   if (IsWindowAvailable()) {
     DetachFromNSWindow();
   } else {
     mWnd = nullptr;
   }
 }
 nsresult
 TaskbarTabPreview::ShowActive(bool active) {
   NS_ASSERTION(mVisible && CanMakeTaskbarCalls(), "ShowActive called on invisible window or before taskbar calls can be made for this window");
   return FAILED(mTaskbar->SetTabActive(active ? mProxyWindow : nullptr,
                                        mWnd, 0)) ? NS_ERROR_FAILURE : NS_OK;
 }
 HWND &
 TaskbarTabPreview::PreviewWindow() {
   return mProxyWindow;
 }
 nativeWindow
 TaskbarTabPreview::GetHWND() {
   return mProxyWindow;
 }
 void
 TaskbarTabPreview::EnsureRegistration() {
   NS_ASSERTION(mVisible && CanMakeTaskbarCalls(), "EnsureRegistration called when it is not safe to do so");
   (void) UpdateTaskbarProperties();
 }
 NS_IMETHODIMP
 TaskbarTabPreview::GetTitle(nsAString &aTitle) {
   aTitle = mTitle;
   return NS_OK;
 }
 NS_IMETHODIMP
 TaskbarTabPreview::SetTitle(const nsAString &aTitle) {
   mTitle = aTitle;
   return mVisible ? UpdateTitle() : NS_OK;
 }
 NS_IMETHODIMP
 TaskbarTabPreview::SetIcon(imgIContainer *icon) {
   HICON hIcon = nullptr;
   if (icon) {
     nsresult rv;
     rv = nsWindowGfx::CreateIcon(icon, false, 0, 0,
                                  nsWindowGfx::GetIconMetrics(nsWindowGfx::kSmallIcon),
                                  &hIcon);
     NS_ENSURE_SUCCESS(rv, rv);
   }
   if (mIcon)
     ::DestroyIcon(mIcon);
   mIcon = hIcon;
   mIconImage = icon;
   return mVisible ? UpdateIcon() : NS_OK;
 }
 NS_IMETHODIMP
 TaskbarTabPreview::GetIcon(imgIContainer **icon) {
   NS_IF_ADDREF(*icon = mIconImage);
   return NS_OK;
 }
 NS_IMETHODIMP
 TaskbarTabPreview::Move(nsITaskbarTabPreview *aNext) {
   if (aNext == this)
     return NS_ERROR_INVALID_ARG;
   mNext = aNext;
   return CanMakeTaskbarCalls() ? UpdateNext() : NS_OK;
 }
 nsresult
 TaskbarTabPreview::UpdateTaskbarProperties() {
   if (mRegistered)
     return NS_OK;
   if (FAILED(mTaskbar->RegisterTab(mProxyWindow, mWnd)))
     return NS_ERROR_FAILURE;
   nsresult rv = UpdateNext();
   NS_ENSURE_SUCCESS(rv, rv);
   rv = TaskbarPreview::UpdateTaskbarProperties();
   mRegistered = true;
   return rv;
 }
 LRESULT
 TaskbarTabPreview::WndProc(UINT nMsg, WPARAM wParam, LPARAM lParam) {
   nsRefPtr<TaskbarTabPreview> kungFuDeathGrip(this);
   switch (nMsg) {
     case WM_CREATE:
       TaskbarPreview::EnableCustomDrawing(mProxyWindow, true);
       return 0;
     case WM_CLOSE:
       mController->OnClose();
       return 0;
     case WM_ACTIVATE:
       if (LOWORD(wParam) == WA_ACTIVE) {
         // Activate the tab the user selected then restore the main window,
         // keeping normal/max window state intact.
         bool activateWindow;
         nsresult rv = mController->OnActivate(&activateWindow);
         if (NS_SUCCEEDED(rv) && activateWindow) {
           nsWindow* win = WinUtils::GetNSWindowPtr(mWnd);
           if (win) {
             nsWindow * parent = win->GetTopLevelWindow(true);
             if (parent) {
               parent->Show(true);
             }
           }
         }
       }
       return 0;
     case WM_GETICON:
       return (LRESULT)mIcon;
     case WM_SYSCOMMAND:
       // Send activation events to the top level window and select the proper
       // tab through the controller.
       if (wParam == SC_RESTORE || wParam == SC_MAXIMIZE) {
         bool activateWindow;
         nsresult rv = mController->OnActivate(&activateWindow);
         if (NS_SUCCEEDED(rv) && activateWindow) {
           // Note, restoring an iconic, maximized window here will only
           // activate the maximized window. This is not a bug, it's default
           // windows behavior.
           ::SendMessageW(mWnd, WM_SYSCOMMAND, wParam, lParam);
         }
         return 0;
       }
       // Forward everything else to the top level window. Do not forward
       // close since that's intended for the tab. When the preview proxy
       // closes, we'll close the tab above.
       return wParam == SC_CLOSE
            ? ::DefWindowProcW(mProxyWindow, WM_SYSCOMMAND, wParam, lParam)
            : ::SendMessageW(mWnd, WM_SYSCOMMAND, wParam, lParam);
       return 0;
   }
   return TaskbarPreview::WndProc(nMsg, wParam, lParam);
 }
 /* static */
 LRESULT CALLBACK
 TaskbarTabPreview::GlobalWndProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam) {
   TaskbarTabPreview *preview(nullptr);
   if (nMsg == WM_CREATE) {
     CREATESTRUCT *cs = reinterpret_cast<CREATESTRUCT*>(lParam);
     preview = reinterpret_cast<TaskbarTabPreview*>(cs->lpCreateParams);
     if (!::SetPropW(hWnd, TASKBARPREVIEW_HWNDID, preview))
       NS_ERROR("Could not associate native window with tab preview");
     preview->mProxyWindow = hWnd;
   } else {
     preview = reinterpret_cast<TaskbarTabPreview*>(::GetPropW(hWnd, TASKBARPREVIEW_HWNDID));
     if (nMsg == WM_DESTROY)
       ::RemovePropW(hWnd, TASKBARPREVIEW_HWNDID);
   }
   if (preview)
     return preview->WndProc(nMsg, wParam, lParam);
   return ::DefWindowProcW(hWnd, nMsg, wParam, lParam);
 }
 nsresult
 TaskbarTabPreview::Enable() {
   WNDCLASSW wc;
   HINSTANCE module = GetModuleHandle(nullptr);
   if (!GetClassInfoW(module, kWindowClass, &wc)) {
     wc.style         = 0;
     wc.lpfnWndProc   = GlobalWndProc;
     wc.cbClsExtra    = 0;
     wc.cbWndExtra    = 0;
     wc.hInstance     = module;
     wc.hIcon         = nullptr;
     wc.hCursor       = nullptr;
     wc.hbrBackground = (HBRUSH) nullptr;
     wc.lpszMenuName  = (LPCWSTR) nullptr;
     wc.lpszClassName = kWindowClass;
     RegisterClassW(&wc);
   }
   ::CreateWindowW(kWindowClass, L"TaskbarPreviewWindow",
                   WS_CAPTION | WS_SYSMENU, 0, 0, 200, 60,
                   nullptr, nullptr, module, this);
   // GlobalWndProc will set mProxyWindow so that WM_CREATE can have a valid HWND
   if (!mProxyWindow)
     return NS_ERROR_INVALID_ARG;
   UpdateProxyWindowStyle();
   nsresult rv = TaskbarPreview::Enable();
   nsresult rvUpdate;
   rvUpdate = UpdateTitle();
   if (NS_FAILED(rvUpdate))
     rv = rvUpdate;
   rvUpdate = UpdateIcon();
   if (NS_FAILED(rvUpdate))
     rv = rvUpdate;
   return rv;
 }
 nsresult
 TaskbarTabPreview::Disable() {
   // TaskbarPreview::Disable assumes that mWnd is valid but this method can be
   // called when it is null iff the nsWindow has already been destroyed and we
   // are still visible for some reason during object destruction.
   if (mWnd)
     TaskbarPreview::Disable();
   if (FAILED(mTaskbar->UnregisterTab(mProxyWindow)))
     return NS_ERROR_FAILURE;
   mRegistered = false;
   // TaskbarPreview::WndProc will set mProxyWindow to null
   if (!DestroyWindow(mProxyWindow))
     return NS_ERROR_FAILURE;
   mProxyWindow = nullptr;
   return NS_OK;
 }
 void
 TaskbarTabPreview::DetachFromNSWindow() {
   (void) SetVisible(false);
   WindowHook &hook = GetWindowHook();
   hook.RemoveMonitor(WM_WINDOWPOSCHANGED, MainWindowHook, this);
   TaskbarPreview::DetachFromNSWindow();
 }
 /* static */
 bool
 TaskbarTabPreview::MainWindowHook(void *aContext,
                                   HWND hWnd, UINT nMsg,
                                   WPARAM wParam, LPARAM lParam,
                                   LRESULT *aResult) {
   if (nMsg == WM_WINDOWPOSCHANGED) {
     TaskbarTabPreview *preview = reinterpret_cast<TaskbarTabPreview*>(aContext);
     WINDOWPOS *pos = reinterpret_cast<WINDOWPOS*>(lParam);
     if (SWP_FRAMECHANGED == (pos->flags & SWP_FRAMECHANGED))
       preview->UpdateProxyWindowStyle();
   } else {
     NS_NOTREACHED("Style changed hook fired on non-style changed message");
   }
   return false;
 }
 void
 TaskbarTabPreview::UpdateProxyWindowStyle() {
   if (!mProxyWindow)
     return;
   DWORD minMaxMask = WS_MINIMIZE | WS_MAXIMIZE;
   DWORD windowStyle = GetWindowLongW(mWnd, GWL_STYLE);
   DWORD proxyStyle = GetWindowLongW(mProxyWindow, GWL_STYLE);
   proxyStyle &= ~minMaxMask;
   proxyStyle |= windowStyle & minMaxMask;
   SetWindowLongW(mProxyWindow, GWL_STYLE, proxyStyle);
   DWORD exStyle = (WS_MAXIMIZE == (windowStyle & WS_MAXIMIZE)) ? WS_EX_TOOLWINDOW : 0;
   SetWindowLongW(mProxyWindow, GWL_EXSTYLE, exStyle);
 }
 nsresult
 TaskbarTabPreview::UpdateTitle() {
   NS_ASSERTION(mVisible, "UpdateTitle called on invisible preview");
   if (!::SetWindowTextW(mProxyWindow, mTitle.get()))
     return NS_ERROR_FAILURE;
   return NS_OK;
 }
 nsresult
 TaskbarTabPreview::UpdateIcon() {
   NS_ASSERTION(mVisible, "UpdateIcon called on invisible preview");
   ::SendMessageW(mProxyWindow, WM_SETICON, ICON_SMALL, (LPARAM)mIcon);
   return NS_OK;
 }
 nsresult
 TaskbarTabPreview::UpdateNext() {
   NS_ASSERTION(CanMakeTaskbarCalls() && mVisible, "UpdateNext called on invisible tab preview");
   HWND hNext = nullptr;
   if (mNext) {
     bool visible;
     nsresult rv = mNext->GetVisible(&visible);
     NS_ENSURE_SUCCESS(rv, rv);
     // Can only move next to enabled previews
     if (!visible)
       return NS_ERROR_FAILURE;
     hNext = (HWND)mNext->GetHWND();
     // hNext must be registered with the taskbar if the call is to succeed
     mNext->EnsureRegistration();
   }
   if (FAILED(mTaskbar->SetTabOrder(mProxyWindow, hNext)))
     return NS_ERROR_FAILURE;
   return NS_OK;
 }
 } // namespace widget
 } // namespace mozilla

The Tor Browser / annotate

widget/windows/TaskbarTabPreview.cpp@ac0c01689b40 (annotated)

widget/windows/TaskbarTabPreview.cpp