Use a flag to grant a temporary URI permission.

It turns out that we can let the system to call
InputMethodService#exposeContent(InputContentInfo, EditorInfo), which
added in my previous CL [1], during the IME is calling
InputConnection#commitContent() as follows.

  [IME]
  InputContentInfo contentInfo = new InputContentInfo(
          contentUri,
          new ClipDescription(description, new String[]{mimeType}),
          linkUrl);
  getCurrentInputConnection().commitContent(
          inputContentInfo,
          InputConnection.INPUT_CONTENT_GRANT_READ_URI_PERMISSION,
          null);

  [App]
  try {
      contentInfo.requestPermission();
      // Load inputContentInfo.getContentUri() here.
  } finally {
      contentInfo.releasePermission();
  }

This gives us flexibility to let InputConnection#commitContent() do all
the magic for IME developers like other APIs such as
Context#startActivity(), rather than asking them to call one more API to
grant a temporary URI permission like a scenario where
Context#grantUriPermission() is used.

 [1]: I2772889ca01f2ecb2cdeed4e04a9319bdf7bc5a6
      25e0813e6eb6315b1016db805fa9b791b4ae5cc2

Bug: 29450031
Change-Id: I99536cd58c9984af30b0bafb4a1dd25a26634a2d

1 files changed, 26 insertions, 2 deletions

diff --git a/core/java/android/inputmethodservice/AbstractInputMethodService.java b/core/java/android/inputmethodservice/AbstractInputMethodService.java
index 3531926d347c..29177b6b47cf 100644
--- a/core/java/android/inputmethodservice/AbstractInputMethodService.java
+++ b/core/java/android/inputmethodservice/AbstractInputMethodService.java
@@ -16,11 +16,14 @@
 
 package android.inputmethodservice;
 
+import android.annotation.NonNull;
 import android.app.Service;
 import android.content.Intent;
 import android.os.IBinder;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
+import android.view.inputmethod.InputConnection;
+import android.view.inputmethod.InputContentInfo;
 import android.view.inputmethod.InputMethod;
 import android.view.inputmethod.InputMethodSession;
 
@@ -208,7 +211,7 @@ public abstract class AbstractInputMethodService extends Service
      *
      * @param event The motion event being received.
      * @return True if the event was handled in this function, false otherwise.
-     * @see View#onTrackballEvent
+     * @see android.view.View#onTrackballEvent(MotionEvent)
      */
     public boolean onTrackballEvent(MotionEvent event) {
         return false;
@@ -219,9 +222,30 @@ public abstract class AbstractInputMethodService extends Service
      *
      * @param event The motion event being received.
      * @return True if the event was handled in this function, false otherwise.
-     * @see View#onGenericMotionEvent
+     * @see android.view.View#onGenericMotionEvent(MotionEvent)
      */
     public boolean onGenericMotionEvent(MotionEvent event) {
         return false;
     }
+
+    /**
+     * Allow the receiver of {@link InputContentInfo} to obtain a temporary read-only access
+     * permission to the content.
+     *
+     * <p>Default implementation does nothing.</p>
+     *
+     * @param inputContentInfo Content to be temporarily exposed from the input method to the
+     * application.
+     * This cannot be {@code null}.
+     * @param inputConnection {@link InputConnection} with which
+     * {@link InputConnection#commitContent(InputContentInfo, int, android.os.Bundle)} will be
+     * called.
+     * @return {@code false} if we cannot allow a temporary access permission.
+     * @hide
+     */
+    public void exposeContent(@NonNull InputContentInfo inputContentInfo,
+            @NonNull InputConnection inputConnection) {
+        return;
+    }
+
 }