Add InputMethodService#exposeContent()

This is a follow up CL to my previous CLs [1][2] that introduced
InputConnection#commitContent(InputContentInfo, Bundle) API to enable
IMEs to send a content to the target application.

With this CL, IME developers are able to temporarily expose
InputContentInfo object to the target package without permanently
granting URI permission.  Although calling IMS#exposeContent() is
allowed only for the IME that is currently selected, the client is able
to request a temporary read-only access even after the current IME is
switched to any other IME as long as the client keeps InputContentInfo
object.

Here is a sample code snippet about how to use this mechanism.

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

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

 [1]: Iaadf934a997ffcd6000a516cc3c1873db56e60ad
      152944f4909c47917473293b258d266435c6ab35
 [2]: Ica1ba3154795c1bf44e140dfe639b299f83cd8af
      adebb52588b098a1af678d4e33a234ef1ce783b2

Bug: 29450031
Change-Id: I2772889ca01f2ecb2cdeed4e04a9319bdf7bc5a6

1 files changed, 35 insertions, 0 deletions

diff --git a/core/java/android/inputmethodservice/InputMethodService.java b/core/java/android/inputmethodservice/InputMethodService.java
index 4799773d9ed6..8e0e0b0e4b9a 100644
--- a/core/java/android/inputmethodservice/InputMethodService.java
+++ b/core/java/android/inputmethodservice/InputMethodService.java
@@ -23,6 +23,7 @@ import android.annotation.CallSuper;
 import android.annotation.DrawableRes;
 import android.annotation.IntDef;
 import android.annotation.MainThread;
+import android.annotation.NonNull;
 import android.app.ActivityManager;
 import android.app.Dialog;
 import android.content.Context;
@@ -65,6 +66,7 @@ import android.view.inputmethod.ExtractedText;
 import android.view.inputmethod.ExtractedTextRequest;
 import android.view.inputmethod.InputBinding;
 import android.view.inputmethod.InputConnection;
+import android.view.inputmethod.InputContentInfo;
 import android.view.inputmethod.InputMethod;
 import android.view.inputmethod.InputMethodManager;
 import android.view.inputmethod.InputMethodSubtype;
@@ -2598,6 +2600,39 @@ public class InputMethodService extends AbstractInputMethodService {
     }
 
     /**
+     * Allow the receiver of {@link InputContentInfo} to obtain a temporary read-only access
+     * permission to the content.
+     *
+     * <p>Make sure that the content provider owning the Uri sets the
+     * {@link android.R.styleable#AndroidManifestProvider_grantUriPermissions
+     * grantUriPermissions} attribute in its manifest or included the
+     * {@link android.R.styleable#AndroidManifestGrantUriPermission
+     * &lt;grant-uri-permissions&gt;} tag. Otherwise {@link InputContentInfo#requestPermission()}
+     * can fail.</p>
+     *
+     * <p>Although calling this API is allowed only for the IME that is currently selected, the
+     * client is able to request a temporary read-only access even after the current IME is switched
+     * to any other IME as long as the client keeps {@link InputContentInfo} object.</p>
+     *
+     * @param inputContentInfo Content to be temporarily exposed from the input method to the
+     * application.
+     * This cannot be {@code null}.
+     * @param editorInfo The editor that receives {@link InputContentInfo}.
+     * @return {@code false} if we cannot allow a temporary access permission.
+     */
+    public final boolean exposeContent(@NonNull InputContentInfo inputContentInfo,
+            @NonNull EditorInfo editorInfo) {
+        if (inputContentInfo == null) {
+            throw new NullPointerException("inputContentInfo");
+        }
+        if (editorInfo == null) {
+            throw new NullPointerException("editorInfo");
+        }
+
+        return mImm.exposeContent(mToken, inputContentInfo, editorInfo);
+    }
+
+    /**
      * Performs a dump of the InputMethodService's internal state.  Override
      * to add your own information to the dump.
      */