Adds a new private API - getSurroundingText for the IME extension.

Change-Id: Iba7d37b3698e2092cd0cba6b117505e03ab912ff
Reviewed-on: https://chromium-review.googlesource.com/1111748
Commit-Queue: Shu Chen <shuchen@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570311}

chrome/browser/chromeos/extensions/input_method_api.cc

@@ -38,6 +38,7 @@
 #include "ui/base/ime/chromeos/input_method_descriptor.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
 #include "ui/base/ime/chromeos/input_method_util.h"
+#include "ui/base/ime/ime_bridge.h"
 #include "ui/keyboard/keyboard_controller.h"
 #include "ui/keyboard/keyboard_util.h"
 
@@ -59,6 +60,8 @@ namespace OnImeMenuListChanged =
     extensions::api::input_method_private::OnImeMenuListChanged;
 namespace OnImeMenuItemsChanged =
     extensions::api::input_method_private::OnImeMenuItemsChanged;
+namespace GetSurroundingText =
+    extensions::api::input_method_private::GetSurroundingText;
 
 namespace {
 
@@ -296,6 +299,50 @@ InputMethodPrivateOpenOptionsPageFunction::Run() {
 #endif
 }
 
+ExtensionFunction::ResponseAction
+InputMethodPrivateGetSurroundingTextFunction::Run() {
+#if !defined(OS_CHROMEOS)
+  EXTENSION_FUNCTION_VALIDATE(false);
+#else
+  ui::IMEInputContextHandlerInterface* input_context =
+      ui::IMEBridge::Get()->GetInputContextHandler();
+  if (!input_context)
+    return RespondNow(Error("No input context handler."));
+
+  std::unique_ptr<GetSurroundingText::Params> params(
+      GetSurroundingText::Params::Create(*args_));
+  if (params->before_length < 0 || params->after_length < 0)
+    return RespondNow(Error("Invalid parameters."));
+
+  uint32_t param_before_length = (uint32_t)params->before_length;
+  uint32_t param_after_length = (uint32_t)params->after_length;
+
+  auto ret = std::make_unique<base::DictionaryValue>();
+  ui::SurroundingTextInfo info = input_context->GetSurroundingTextInfo();
+  uint32_t text_before_end = info.selection_range.start();
+  uint32_t text_before_start = text_before_end > param_before_length
+                                   ? text_before_end - param_before_length
+                                   : 0;
+  uint32_t text_after_start = info.selection_range.end();
+  uint32_t text_after_end =
+      text_after_start + param_after_length < info.surrounding_text.length()
+          ? text_after_start + param_after_length
+          : info.surrounding_text.length();
+
+  ret->SetString("before",
+                 info.surrounding_text.substr(
+                     text_before_start, text_before_end - text_before_start));
+  ret->SetString("selected",
+                 info.surrounding_text.substr(
+                     text_before_end, text_after_start - text_before_end));
+  ret->SetString(
+      "after", info.surrounding_text.substr(text_after_start,
+                                            text_after_end - text_after_start));
+
+  return RespondNow(OneArgument(std::move(ret)));
+#endif
+}
+
 InputMethodAPI::InputMethodAPI(content::BrowserContext* context)
     : context_(context) {
   EventRouter::Get(context_)->RegisterObserver(this, OnChanged::kEventName);

chrome/browser/chromeos/extensions/input_method_api.h

@@ -192,6 +192,22 @@ class InputMethodPrivateOpenOptionsPageFunction
   DISALLOW_COPY_AND_ASSIGN(InputMethodPrivateOpenOptionsPageFunction);
 };
 
+class InputMethodPrivateGetSurroundingTextFunction
+    : public UIThreadExtensionFunction {
+ public:
+  InputMethodPrivateGetSurroundingTextFunction() {}
+
+ protected:
+  ~InputMethodPrivateGetSurroundingTextFunction() override {}
+
+  ResponseAction Run() override;
+
+ private:
+  DECLARE_EXTENSION_FUNCTION("inputMethodPrivate.getSurroundingText",
+                             INPUTMETHODPRIVATE_GETSURROUNDINGTEXT)
+  DISALLOW_COPY_AND_ASSIGN(InputMethodPrivateGetSurroundingTextFunction);
+};
+
 class InputMethodAPI : public BrowserContextKeyedAPI,
                        public extensions::EventRouter::Observer {
  public:

chrome/common/extensions/api/input_method_private.json

@@ -295,6 +295,39 @@
             ]
           }
         ]
+      }, {
+        "name": "getSurroundingText",
+        "type": "function",
+        "description": "Gets the surrounding text of the current selection",
+        "parameters": [
+          {
+            "name": "beforeLength",
+            "type": "integer",
+            "description": "The number of characters before the current selection."
+          },
+          {
+            "name": "afterLength",
+            "type": "integer",
+            "description": "The number of characters after the current selection."
+          },
+          {
+            "type": "function",
+            "name": "callback",
+            "description": "Callback which is called to provide the result",
+            "parameters": [
+              {
+                "name": "surroundingInfo",
+                "type": "object",
+                "description": "The surrouding text info.",
+                "properties": {
+                  "before": {"type": "string"},
+                  "selected": {"type": "string"},
+                  "after": {"type": "string"}
+                }
+              }
+            ]
+          }
+        ]
       }
     ],
     "events": [

extensions/browser/extension_function_histogram_value.h

@@ -1321,6 +1321,7 @@ enum HistogramValue {
   VIRTUALKEYBOARDPRIVATE_SETOCCLUDEDBOUNDS = 1258,
   SYSTEM_POWER_SOURCE_GETPOWERSOURCEINFO = 1259,
   SYSTEM_POWER_SOURCE_REQUESTSTATUSUPDATE = 1260,
+  INPUTMETHODPRIVATE_GETSURROUNDINGTEXT = 1261,
   // Last entry: Add new entries above, then run:
   // python tools/metrics/histograms/update_extension_histograms.py
   ENUM_BOUNDARY

tools/metrics/histograms/enums.xml

@@ -15778,6 +15778,7 @@ Called by update_net_error_codes.py.-->
   <int value="1258" label="VIRTUALKEYBOARDPRIVATE_SETOCCLUDEDBOUNDS"/>
   <int value="1259" label="SYSTEM_POWER_SOURCE_GETPOWERSOURCEINFO"/>
   <int value="1260" label="SYSTEM_POWER_SOURCE_REQUESTSTATUSUPDATE"/>
+  <int value="1261" label="INPUTMETHODPRIVATE_GETSURROUNDINGTEXT"/>
 </enum>
 
 <enum name="ExtensionIconState">

ui/base/ime/ime_input_context_handler_interface.h

@@ -15,6 +15,11 @@
 
 namespace ui {
 
+struct SurroundingTextInfo {
+  base::string16 surrounding_text;
+  gfx::Range selection_range;
+};
+
 class UI_BASE_IME_EXPORT IMEInputContextHandlerInterface {
  public:
   // Called when the engine commit a text.
@@ -28,6 +33,9 @@ class UI_BASE_IME_EXPORT IMEInputContextHandlerInterface {
   // Called when the engine request deleting surrounding string.
   virtual void DeleteSurroundingText(int32_t offset, uint32_t length) = 0;
 
+  // Called from the extension API.
+  virtual SurroundingTextInfo GetSurroundingTextInfo() = 0;
+
   // Called when the engine sends a key event.
   virtual void SendKeyEvent(KeyEvent* event) = 0;
 

ui/base/ime/input_method_base.cc

@@ -267,6 +267,18 @@ void InputMethodBase::UpdateCompositionText(const CompositionText& composition_,
 
 void InputMethodBase::DeleteSurroundingText(int32_t offset, uint32_t length) {}
 
+SurroundingTextInfo InputMethodBase::GetSurroundingTextInfo() {
+  gfx::Range text_range;
+  SurroundingTextInfo info;
+  TextInputClient* client = GetTextInputClient();
+  if (!client->GetTextRange(&text_range) ||
+      !client->GetTextFromRange(text_range, &info.surrounding_text) ||
+      !client->GetSelectionRange(&info.selection_range)) {
+    return SurroundingTextInfo();
+  }
+  return info;
+}
+
 void InputMethodBase::SendKeyEvent(KeyEvent* event) {
   sending_key_event_ = true;
   if (track_key_events_for_testing_) {

ui/base/ime/input_method_base.h

@@ -85,6 +85,7 @@ class UI_BASE_IME_EXPORT InputMethodBase
                              uint32_t cursor_pos,
                              bool visible) override;
   void DeleteSurroundingText(int32_t offset, uint32_t length) override;
+  SurroundingTextInfo GetSurroundingTextInfo() override;
   void SendKeyEvent(KeyEvent* event) override;
   InputMethod* GetInputMethod() override;
 

ui/base/ime/mock_ime_input_context_handler.cc

@@ -38,6 +38,10 @@ void MockIMEInputContextHandler::DeleteSurroundingText(int32_t offset,
   last_delete_surrounding_text_arg_.length = length;
 }
 
+SurroundingTextInfo MockIMEInputContextHandler::GetSurroundingTextInfo() {
+  return SurroundingTextInfo();
+}
+
 void MockIMEInputContextHandler::Reset() {
   commit_text_call_count_ = 0;
   update_preedit_text_call_count_ = 0;

ui/base/ime/mock_ime_input_context_handler.h

@@ -36,6 +36,7 @@ class UI_BASE_IME_EXPORT MockIMEInputContextHandler
                              uint32_t cursor_pos,
                              bool visible) override;
   void DeleteSurroundingText(int32_t offset, uint32_t length) override;
+  SurroundingTextInfo GetSurroundingTextInfo() override;
   void SendKeyEvent(KeyEvent* event) override;
   InputMethod* GetInputMethod() override;