Experimental Extension Keybinding (first cut).

Implemented in this cut:

- End-to-end extension keybinding -- in one dimension, that is -- no UI, just basic functionality, such as:
  - Manifest changes to specify keybinding.
  - A simple parser to parse the keybinding from the manifest.
  - An Extension Keybinding Registry object.
  - The ability to open browser action popups, page action popups and send named events to the Extension.

Not implemented:

- All non-Windows specific code.
- Install-success-bubble UI changes (that notify the user of new keybinding -- or of keybinding conflict)
- A UI to show all keybindings and keybinding conflicts, allowing user to reconfigure keybindings.

BUG=27702
TEST=This is tested by an automated test and requires an extension to test manually (one that registers keybinding shortcuts).
Review URL: https://chromiumcodereview.appspot.com/9402018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@123228 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 70 insertions, 9 deletions

diff --git a/ui/base/accelerators/accelerator_manager.cc b/ui/base/accelerators/accelerator_manager.cc
index d2d70c9..034593d 100644
--- a/ui/base/accelerators/accelerator_manager.cc
+++ b/ui/base/accelerators/accelerator_manager.cc
@@ -17,11 +17,29 @@ AcceleratorManager::~AcceleratorManager() {
 }
 
 void AcceleratorManager::Register(const Accelerator& accelerator,
+                                  HandlerPriority priority,
                                   AcceleratorTarget* target) {
-  AcceleratorTargetList& targets = accelerators_[accelerator];
+  AcceleratorTargetList& targets = accelerators_[accelerator].second;
   DCHECK(std::find(targets.begin(), targets.end(), target) == targets.end())
       << "Registering the same target multiple times";
-  targets.push_front(target);
+
+  // All priority accelerators go to the front of the line.
+  if (priority) {
+    DCHECK(!accelerators_[accelerator].first)
+        << "Only one _priority_ handler can be registered";
+    targets.push_front(target);
+    // Mark that we have a priority accelerator at the front.
+    accelerators_[accelerator].first = true;
+    return;
+  }
+
+  // We are registering a normal priority handler. If no priority accelerator
+  // handler has been registered before us, just add the new handler to the
+  // front. Otherwise, register it after the first (only) priority handler.
+  if (!accelerators_[accelerator].first)
+    targets.push_front(target);
+  else
+    targets.insert(++targets.begin(), target);
 }
 
 void AcceleratorManager::Unregister(const Accelerator& accelerator,
@@ -32,7 +50,7 @@ void AcceleratorManager::Unregister(const Accelerator& accelerator,
     return;
   }
 
-  AcceleratorTargetList* targets = &map_iter->second;
+  AcceleratorTargetList* targets = &map_iter->second.second;
   AcceleratorTargetList::iterator target_iter =
       std::find(targets->begin(), targets->end(), target);
   if (target_iter == targets->end()) {
@@ -40,13 +58,19 @@ void AcceleratorManager::Unregister(const Accelerator& accelerator,
     return;
   }
 
+  // Check to see if we have a priority handler and whether we are removing it.
+  if (accelerators_[accelerator].first && target_iter == targets->begin()) {
+    // We've are taking the priority accelerator away, flip the priority flag.
+    accelerators_[accelerator].first = false;
+  }
+
   targets->erase(target_iter);
 }
 
 void AcceleratorManager::UnregisterAll(AcceleratorTarget* target) {
   for (AcceleratorMap::iterator map_iter = accelerators_.begin();
        map_iter != accelerators_.end(); ++map_iter) {
-    AcceleratorTargetList* targets = &map_iter->second;
+    AcceleratorTargetList* targets = &map_iter->second.second;
     targets->remove(target);
   }
 }
@@ -57,7 +81,7 @@ bool AcceleratorManager::Process(const Accelerator& accelerator) {
   if (map_iter != accelerators_.end() && ShouldHandle(accelerator)) {
     // We have to copy the target list here, because an AcceleratorPressed
     // event handler may modify the list.
-    AcceleratorTargetList targets(map_iter->second);
+    AcceleratorTargetList targets(map_iter->second.second);
     for (AcceleratorTargetList::iterator iter = targets.begin();
          iter != targets.end(); ++iter) {
       if ((*iter)->CanHandleAccelerators() &&
@@ -74,9 +98,24 @@ bool AcceleratorManager::Process(const Accelerator& accelerator) {
 AcceleratorTarget* AcceleratorManager::GetCurrentTarget(
     const Accelerator& accelerator) const {
   AcceleratorMap::const_iterator map_iter = accelerators_.find(accelerator);
-  if (map_iter == accelerators_.end() || map_iter->second.empty())
+  if (map_iter == accelerators_.end() || map_iter->second.second.empty())
     return NULL;
-  return map_iter->second.front();
+  return map_iter->second.second.front();
+}
+
+bool AcceleratorManager::HasPriorityHandler(
+    const Accelerator& accelerator) const {
+  AcceleratorMap::const_iterator map_iter = accelerators_.find(accelerator);
+  if (map_iter == accelerators_.end() || map_iter->second.second.empty())
+    return false;
+
+  // Check if we have a priority handler. If not, there's no more work needed.
+  if (!map_iter->second.first)
+    return false;
+
+  // If the priority handler says it cannot handle the accelerator, we must not
+  // count it as one.
+  return map_iter->second.second.front()->CanHandleAccelerators();
 }
 
 bool AcceleratorManager::ShouldHandle(const Accelerator& accelerator) const {
diff --git a/ui/base/accelerators/accelerator_manager.h b/ui/base/accelerators/accelerator_manager.h
index c54ea1d..7164acb 100644
--- a/ui/base/accelerators/accelerator_manager.h
+++ b/ui/base/accelerators/accelerator_manager.h
@@ -8,6 +8,7 @@
 
 #include <list>
 #include <map>
+#include <utility>
 
 #include "base/basictypes.h"
 #include "ui/base/accelerators/accelerator.h"
@@ -19,19 +20,34 @@ namespace ui {
 // The AcceleratorManger is used to handle keyboard accelerators.
 class UI_EXPORT AcceleratorManager {
  public:
+  enum HandlerPriority {
+    kNormalPriority,
+    kHighPriority,
+  };
+
   AcceleratorManager();
   ~AcceleratorManager();
 
   // Register a keyboard accelerator for the specified target. If multiple
   // targets are registered for an accelerator, a target registered later has
   // higher priority.
+  // |accelerator| is the accelerator to register.
+  // |priority| denotes the priority of the handler.
+  // NOTE: In almost all cases, you should specify kPriorityNormal for this
+  // parameter. Setting it to kPriorityHigh prevents Chrome from sending the
+  // shortcut to the webpage if the renderer has focus, which is not desirable
+  // except for very isolated cases.
+  // |target| is the AcceleratorTarget that handles the event once the
+  // accelerator is pressed.
   // Note that we are currently limited to accelerators that are either:
   // - a key combination including Ctrl or Alt
   // - the escape key
   // - the enter key
   // - any F key (F1, F2, F3 ...)
   // - any browser specific keys (as available on special keyboards)
-  void Register(const Accelerator& accelerator, AcceleratorTarget* target);
+  void Register(const Accelerator& accelerator,
+                HandlerPriority priority,
+                AcceleratorTarget* target);
 
   // Unregister the specified keyboard accelerator for the specified target.
   void Unregister(const Accelerator& accelerator, AcceleratorTarget* target);
@@ -52,12 +68,18 @@ class UI_EXPORT AcceleratorManager {
   // accelerator.
   AcceleratorTarget* GetCurrentTarget(const Accelerator& accelertor) const;
 
+  // Whether the given |accelerator| has a priority handler associated with it.
+  bool HasPriorityHandler(const Accelerator& accelerator) const;
+
  private:
   bool ShouldHandle(const Accelerator& accelerator) const;
 
   // The accelerators and associated targets.
   typedef std::list<AcceleratorTarget*> AcceleratorTargetList;
-  typedef std::map<Accelerator, AcceleratorTargetList> AcceleratorMap;
+  // This construct pairs together a |bool| (denoting whether the list contains
+  // a priority_handler at the front) with the list of AcceleratorTargets.
+  typedef std::pair<bool, AcceleratorTargetList> AcceleratorTargets;
+  typedef std::map<Accelerator, AcceleratorTargets> AcceleratorMap;
   AcceleratorMap accelerators_;
 
   // An event passed to Process() last time.