chrome/browser/command_updater.cc

   1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/command_updater.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/logging.h"
  10 #include "base/observer_list.h"
  11 #include "base/stl_util.h"
  12
  13 CommandUpdater::CommandUpdaterDelegate::~CommandUpdaterDelegate() {
  14 }
  15
  16 class CommandUpdater::Command {
  17  public:
  18   bool enabled;
  19   ObserverList<CommandObserver> observers;
  20
  21   Command() : enabled(true) {}
  22 };
  23
  24 CommandUpdater::CommandUpdater(CommandUpdaterDelegate* handler)
  25     : delegate_(handler) {
  26 }
  27
  28 CommandUpdater::~CommandUpdater() {
  29   STLDeleteContainerPairSecondPointers(commands_.begin(), commands_.end());
  30 }
  31
  32 bool CommandUpdater::IsCommandEnabled(int id) const {
  33   const CommandMap::const_iterator command(commands_.find(id));
  34   if (command == commands_.end())
  35     return false;
  36   return command->second->enabled;
  37 }
  38
  39 bool CommandUpdater::SupportsCommand(int id) const {
  40   return commands_.find(id) != commands_.end();
  41 }
  42
  43 void CommandUpdater::ExecuteCommand(int id) {
  44   if (IsCommandEnabled(id))
  45     delegate_->ExecuteCommand(id);
  46 }
  47
  48 CommandUpdater::CommandObserver::~CommandObserver() {
  49 }
  50
  51 void CommandUpdater::UpdateCommandEnabled(int id, bool enabled) {
  52   Command* command = GetCommand(id, true);
  53   if (command->enabled == enabled)
  54     return;  // Nothing to do.
  55   command->enabled = enabled;
  56   FOR_EACH_OBSERVER(CommandObserver, command->observers,
  57                     EnabledStateChangedForCommand(id, enabled));
  58 }
  59
  60 CommandUpdater::Command* CommandUpdater::GetCommand(int id, bool create) {
  61   bool supported = SupportsCommand(id);
  62   if (supported)
  63     return commands_[id];
  64   DCHECK(create);
  65   Command* command = new Command;
  66   commands_[id] = command;
  67   return command;
  68 }
  69
  70 void CommandUpdater::AddCommandObserver(int id, CommandObserver* observer) {
  71   GetCommand(id, true)->observers.AddObserver(observer);
  72 }
  73
  74 void CommandUpdater::RemoveCommandObserver(int id, CommandObserver* observer) {
  75   GetCommand(id, false)->observers.RemoveObserver(observer);
  76 }
  77
  78 void CommandUpdater::RemoveCommandObserver(CommandObserver* observer) {
  79   for (CommandMap::const_iterator it = commands_.begin();
  80        it != commands_.end();
  81        ++it) {
  82     Command* command = it->second;
  83     if (command)
  84       command->observers.RemoveObserver(observer);
  85   }
  86 }