The Tor Browser: widget/windows/WindowHook.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-

     2  *

     3  * This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "WindowHook.h"

     8 #include "nsWindow.h"

     9 #include "nsWindowDefs.h"

    11 namespace mozilla {

    12 namespace widget {

    14 nsresult

    15 WindowHook::AddHook(UINT nMsg, Callback callback, void *context) {

    16   MessageData *data = LookupOrCreate(nMsg);

    18   if (!data)

    19     return NS_ERROR_OUT_OF_MEMORY;

    21   // Ensure we don't overwrite another hook

    22   NS_ENSURE_TRUE(nullptr == data->hook.cb, NS_ERROR_UNEXPECTED);

    24   data->hook = CallbackData(callback, context);

    26   return NS_OK;

    27 }

    29 nsresult

    30 WindowHook::RemoveHook(UINT nMsg, Callback callback, void *context) {

    31   CallbackData cbdata(callback, context);

    32   MessageData *data = Lookup(nMsg);

    33   if (!data)

    34     return NS_ERROR_UNEXPECTED;

    35   if (data->hook != cbdata)

    36     return NS_ERROR_UNEXPECTED;

    37   data->hook = CallbackData();

    39   DeleteIfEmpty(data);

    40   return NS_OK;

    41 }

    43 nsresult

    44 WindowHook::AddMonitor(UINT nMsg, Callback callback, void *context) {

    45   MessageData *data = LookupOrCreate(nMsg);

    46   return (data && data->monitors.AppendElement(CallbackData(callback, context)))

    47          ? NS_OK : NS_ERROR_OUT_OF_MEMORY;

    48 }

    50 nsresult

    51 WindowHook::RemoveMonitor(UINT nMsg, Callback callback, void *context) {

    52   CallbackData cbdata(callback, context);

    53   MessageData *data = Lookup(nMsg);

    54   if (!data)

    55     return NS_ERROR_UNEXPECTED;

    56   CallbackDataArray::index_type idx = data->monitors.IndexOf(cbdata);

    57   if (idx == CallbackDataArray::NoIndex)

    58     return NS_ERROR_UNEXPECTED;

    59   data->monitors.RemoveElementAt(idx);

    60   DeleteIfEmpty(data);

    61   return NS_OK;

    62 }

    64 WindowHook::MessageData *

    65 WindowHook::Lookup(UINT nMsg) {

    66   MessageDataArray::index_type idx;

    67   for (idx = 0; idx < mMessageData.Length(); idx++) {

    68     MessageData &data = mMessageData[idx];

    69     if (data.nMsg == nMsg)

    70       return &data;

    71   }

    72   return nullptr;

    73 }

    75 WindowHook::MessageData *

    76 WindowHook::LookupOrCreate(UINT nMsg) {

    77   MessageData *data = Lookup(nMsg);

    78   if (!data) {

    79     data = mMessageData.AppendElement();

    81     if (!data)

    82       return nullptr;

    84     data->nMsg = nMsg;

    85   }

    86   return data;

    87 }

    89 void

    90 WindowHook::DeleteIfEmpty(MessageData *data) {

    91   // Never remove a MessageData that has still a hook or monitor entries.

    92   if (data->hook || !data->monitors.IsEmpty())

    93     return;

    95   MessageDataArray::index_type idx;

    96   idx = data - mMessageData.Elements();

    97   NS_ASSERTION(idx >= 0 && idx < mMessageData.Length(), "Attempted to delete MessageData that doesn't belong to this array!");

    98   mMessageData.RemoveElementAt(idx);

    99 }

   101 bool

   102 WindowHook::Notify(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam,

   103                    MSGResult& aResult)

   104 {

   105   MessageData *data = Lookup(nMsg);

   106   if (!data)

   107     return false;

   109   uint32_t length = data->monitors.Length();

   110   for (uint32_t midx = 0; midx < length; midx++) {

   111     data->monitors[midx].Invoke(hWnd, nMsg, wParam, lParam, &aResult.mResult);

   112   }

   114   aResult.mConsumed =

   115     data->hook.Invoke(hWnd, nMsg, wParam, lParam, &aResult.mResult);

   116   return aResult.mConsumed;

   117 }

   119 bool

   120 WindowHook::CallbackData::Invoke(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam,

   121                                  LRESULT *aResult) {

   122   if (!cb)

   123     return false;

   124   return cb(context, hWnd, msg, wParam, lParam, aResult);

   125 }

   126 } // namespace widget

   127 } // namespace mozilla

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