Support dragging texts out of webview/Chrome.

content/browser/web_contents/web_contents_view_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/web_contents/web_contents_view_android.h"
 
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
 #include "base/logging.h"
 #include "content/browser/android/content_view_core_impl.h"
 #include "content/browser/frame_host/interstitial_page_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_android.h"
 #include "content/browser/renderer_host/render_view_host_factory.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/common/drop_data.h"
+#include "ui/gfx/android/java_bitmap.h"
+#include "ui/gfx/image/image_skia.h"
+
+using base::android::AttachCurrentThread;
+using base::android::ConvertUTF16ToJavaString;
+using base::android::JavaRef;
+using base::android::ScopedJavaLocalRef;
 
 namespace content {
 
 WebContentsView* CreateWebContentsView(
     WebContentsImpl* web_contents,
     WebContentsViewDelegate* delegate,
     RenderViewHostDelegateView** render_view_host_delegate_view) {
   WebContentsViewAndroid* rv = new WebContentsViewAndroid(
       web_contents, delegate);
   *render_view_host_delegate_view = rv;
@@ skipping 165 matching lines @@
   if (content_view_core_)
     content_view_core_->HideSelectPopupMenu();
 }
 
 void WebContentsViewAndroid::StartDragging(
     const DropData& drop_data,
     blink::WebDragOperationsMask allowed_ops,
     const gfx::ImageSkia& image,
     const gfx::Vector2d& image_offset,
     const DragEventSourceInfo& event_info) {
-  NOTIMPLEMENTED();
+  if (drop_data.text.is_null())
+    return;
+
+  gfx::NativeView native_view = GetNativeView();
+  if (!native_view)
+    return;
+
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jstring> jtext =
+      ConvertUTF16ToJavaString(env, drop_data.text.string());
+
+  native_view->StartDragAndDrop(jtext,

[sgurun-gerrit only, 2016/07/14 18:13:35]

it is better to convert the java type in location where you actually need. It
seems the right place is window_android. Is there any need to do it here?

[hush (inactive), 2016/07/14 18:37:07]

because window_android is in ui and cannot depend on content/. We need
content::DropData if we were to convert the data to java type here.

[sgurun-gerrit only, 2016/07/14 18:43:04]

ok in this case, I am fine.

Daniel:

By converting the data to a java type and passing to WindowAndroid we are making
it opaque to WindowAndroid. In your new design, is the final role for
WindowAndroid being a class just transferring such data to Java side? 

[no sievers, 2016/07/14 20:31:13]

I think we'll probably want to eventually just add JNI to ViewAndroid(Delegate),
bypassing WindowAndroid (since this is going to the container view).

+                                gfx::ConvertToJavaBitmap(image.bitmap()));
+
+  if (content_view_core_)
+    content_view_core_->HidePopupsAndPreserveSelection();
 }
 
 void WebContentsViewAndroid::UpdateDragCursor(blink::WebDragOperation op) {
   // Intentional no-op because Android does not have cursor.
 }
 
 void WebContentsViewAndroid::OnDragEntered(
     const std::vector<DropData::Metadata>& metadata,
     const gfx::Point& location,
     const gfx::Point& screen_location) {
+  blink::WebDragOperationsMask allowed_ops =
+      static_cast<blink::WebDragOperationsMask>(blink::WebDragOperationCopy |
+                                                blink::WebDragOperationMove);
   web_contents_->GetRenderViewHost()->DragTargetDragEnterWithMetaData(
-      metadata, location, screen_location, blink::WebDragOperationCopy, 0);
+      metadata, location, screen_location, allowed_ops, 0);
 }
 
 void WebContentsViewAndroid::OnDragUpdated(const gfx::Point& location,
                                            const gfx::Point& screen_location) {
+  blink::WebDragOperationsMask allowed_ops =
+      static_cast<blink::WebDragOperationsMask>(blink::WebDragOperationCopy |
+                                                blink::WebDragOperationMove);
   web_contents_->GetRenderViewHost()->DragTargetDragOver(
-      location, screen_location, blink::WebDragOperationCopy, 0);
+      location, screen_location, allowed_ops, 0);
 }
 
 void WebContentsViewAndroid::OnDragExited() {
   web_contents_->GetRenderViewHost()->DragTargetDragLeave();
 }
 
 void WebContentsViewAndroid::OnPerformDrop(DropData* drop_data,
                                            const gfx::Point& location,
                                            const gfx::Point& screen_location) {
   web_contents_->GetRenderViewHost()->FilterDropData(drop_data);
   web_contents_->GetRenderViewHost()->DragTargetDrop(*drop_data, location,
                                                      screen_location, 0);
 }
 
+void WebContentsViewAndroid::OnDragEnded() {
+  web_contents_->GetRenderViewHost()->DragSourceSystemDragEnded();
+}
+
 void WebContentsViewAndroid::GotFocus() {
   // This is only used in the views FocusManager stuff but it bleeds through
   // all subclasses. http://crbug.com/21875
 }
 
 // This is called when we the renderer asks us to take focus back (i.e., it has
 // iterated past the last focusable element on the page).
 void WebContentsViewAndroid::TakeFocus(bool reverse) {
   if (web_contents_->GetDelegate() &&
       web_contents_->GetDelegate()->TakeFocus(web_contents_, reverse))
     return;
   web_contents_->GetRenderWidgetHostView()->Focus();
 }
 
 } // namespace content