gears/base/common/html_event_monitor_ff.cc

   1 // Copyright 2007, Google Inc.
   2 //
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   4 // modification, are permitted provided that the following conditions are met:
   5 //
   6 //  1. Redistributions of source code must retain the above copyright notice,
   7 //     this list of conditions and the following disclaimer.
   8 //  2. Redistributions in binary form must reproduce the above copyright notice,
   9 //     this list of conditions and the following disclaimer in the documentation
  10 //     and/or other materials provided with the distribution.
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  12 //     used to endorse or promote products derived from this software without
  13 //     specific prior written permission.
  14 //
  15 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  16 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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  18 // EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  19 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  21 // OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  22 // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  23 // OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  24 // ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25
  26 #include <gecko_sdk/include/nsIDOMEvent.h>
  27 #include <gecko_sdk/include/nsIDOMEventListener.h>
  28 #include <assert.h>
  29
  30 #include "gears/base/common/html_event_monitor.h"
  31
  32 #include "gears/base/firefox/dom_utils.h"
  33
  34
  35 // Provides an nsIDOMEventListener interface for events to invoke.
  36 class HtmlEventMonitorHook
  37     : public nsIDOMEventListener {
  38  public:
  39   HtmlEventMonitorHook(HtmlEventMonitor::HtmlEventCallback function,
  40                        void *user_param)
  41       : function_(function),
  42         user_param_(user_param) {
  43   }
  44
  45   NS_IMETHOD HandleEvent(nsIDOMEvent *event) {
  46     function_(user_param_);  // invoke user callback
  47     return NS_OK;
  48   }
  49
  50   NS_DECL_ISUPPORTS
  51
  52  private:
  53   nsIDOMEventTarget *orig_target;
  54
  55   HtmlEventMonitor::HtmlEventCallback function_;
  56   void *user_param_;
  57
  58   DISALLOW_EVIL_CONSTRUCTORS(HtmlEventMonitorHook);
  59 };
  60
  61 NS_IMPL_ISUPPORTS1(HtmlEventMonitorHook, nsIDOMEventListener)
  62
  63
  64 //
  65 // HtmlEventMonitor
  66 //
  67
  68 bool HtmlEventMonitor::Start(nsIDOMEventTarget *event_source) {
  69   assert(!event_hook_);
  70   assert(!event_source_);
  71
  72   // create the event hook
  73   scoped_ptr<HtmlEventMonitorHook> event_hook(
  74       new HtmlEventMonitorHook(function_, user_param_));
  75   event_hook->AddRef();
  76
  77   // connect to the event source
  78   nsDependentString firefox_event_name(&event_name_[2]); // skip leading "on"
  79   nsresult nr = event_source->AddEventListener(firefox_event_name,
  80                                                event_hook.get(), PR_FALSE);
  81   if (NS_FAILED(nr)) { return false; }
  82
  83   // only modify data members if everything succeeded
  84   event_hook_ = event_hook.release();
  85   event_source_ = event_source;
  86   return true;
  87 }
  88
  89 void HtmlEventMonitor::Stop() {
  90   assert(event_source_);
  91   assert(event_hook_);
  92
  93   // disconnect from the event source
  94   nsDependentString firefox_event_name(&event_name_[2]); // skip leading "on"
  95   event_source_->RemoveEventListener(firefox_event_name,
  96                                      event_hook_, PR_FALSE);
  97   event_source_ = NULL;
  98
  99   // destroy the event hook
 100   event_hook_->Release();
 101   event_hook_ = NULL;
 102 }