prebuilts/gradle/DragAndDropAcrossApps/DragSource/src/main/java/com/example/android/dragsource/DragSourceFragment.java - platform/developers/build - Git at Google

 /*
  * Copyright 2015, The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
 */

 package com.example.android.dragsource;

 import com.example.android.common.logger.Log;

 import android.content.ClipData;
 import android.content.ClipDescription;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.graphics.Point;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.PersistableBundle;
 import android.support.annotation.Nullable;
 import android.support.v13.view.DragStartHelper;
 import android.support.v4.app.Fragment;
 import android.support.v4.content.FileProvider;
 import android.view.DragEvent;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;

 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.Date;


 /**
  * This sample demonstrates data can be moved between views within the app or between different
  * apps via drag and drop.
  * <p>This is the source app for the drag and drop sample. This app contains several
  * {@link android.widget.ImageView} widgets which can be a drag source. Images can be dropped
  * to a drop target area within the same app or in the DropTarget app (a separate app in this
  * sample).
  * <p>
  * There is also one {@link android.widget.EditText} widget that can be a drag source (no extra
  * setup is necessary).
  * <p/>
  * To enable cross application drag and drop, the {@link android.view.View#DRAG_FLAG_GLOBAL}
  * permission needs to be passed to the {@link android.view.View#startDragAndDrop(ClipData,
  * View.DragShadowBuilder, Object, int)} method. If a Uri
  * requiring permission grants is being sent, then the
  * {@link android.view.View#DRAG_FLAG_GLOBAL_URI_READ} and/or the
  * {@link android.view.View#DRAG_FLAG_GLOBAL_URI_WRITE} flags must be used also.
  */
 public class DragSourceFragment extends Fragment {

     /**
      * Name of saved data that stores the dropped image URI on the local ImageView when set.
      */
     private static final String IMAGE_URI = "IMAGE_URI";

     /**
      * Name of the parameter for a {@link ClipData} extra that stores a text describing the dragged
      * image.
      */
     public static final String EXTRA_IMAGE_INFO = "IMAGE_INFO";

     /**
      * Uri of the ImageView source when set.
      */
     private Uri mLocalImageUri;

     private static final String TAG = "DragSourceFragment";

     private static final String CONTENT_AUTHORITY = "com.example.android.dragsource.fileprovider";

     @Nullable
     @Override
     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
             @Nullable Bundle savedInstanceState) {

         View view = inflater.inflate(R.layout.fragment_dragsource, null);

         // Set up two image views for global drag and drop with a permission grant.
         Uri imageUri = getFileUri(R.drawable.image1, "image1.png");
         ImageView imageView = (ImageView) view.findViewById(R.id.image_one);
         setUpDraggableImage(imageView, imageUri);
         imageView.setImageURI(imageUri);

         imageUri = getFileUri(R.drawable.image2, "image2.png");
         imageView = (ImageView) view.findViewById(R.id.image_two);
         setUpDraggableImage(imageView, imageUri);
         imageView.setImageURI(imageUri);

         // Set up the local drop target area.
         final ImageView localImageTarget = (ImageView) view.findViewById(R.id.local_target);
         localImageTarget.setOnDragListener(new ImageDragListener() {
             @Override
             protected boolean setImageUri(View view, DragEvent event, Uri uri) {
                 mLocalImageUri = uri;
                 Log.d(TAG, "Setting local image to: " + uri);
                 return super.setImageUri(view, event, uri);
             }
         });

         if (savedInstanceState != null) {
             final String uriString = savedInstanceState.getString(IMAGE_URI);
             if (uriString != null) {
                 mLocalImageUri = Uri.parse(uriString);
                 Log.d(TAG, "Restoring local image to: " + mLocalImageUri);
                 localImageTarget.setImageURI(mLocalImageUri);
             }
         }
         return view;
     }

     @Override
     public void onSaveInstanceState(Bundle savedInstanceState) {
         if (mLocalImageUri != null) {
             savedInstanceState.putString(IMAGE_URI, mLocalImageUri.toString());
         }
         super.onSaveInstanceState(savedInstanceState);
     }

     private void setUpDraggableImage(ImageView imageView, final Uri imageUri) {

         // Set up a listener that starts the drag and drop event with flags and extra data.
         DragStartHelper.OnDragStartListener listener = new DragStartHelper.OnDragStartListener() {
             @Override
             public boolean onDragStart(View view, final DragStartHelper helper) {
                 Log.d(TAG, "Drag start event received from helper.");

                 // Use a DragShadowBuilder
                 View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view) {
                     @Override
                     public void onProvideShadowMetrics(Point shadowSize, Point shadowTouchPoint) {
                         super.onProvideShadowMetrics(shadowSize, shadowTouchPoint);
                         // Notify the DragStartHelper of point where the view was touched.
                         helper.getTouchPosition(shadowTouchPoint);
                         Log.d(TAG, "View was touched at: " + shadowTouchPoint);
                     }
                 };

                 // Set up the flags for the drag event.
                 // Enable drag and drop across apps (global)
                 // and require read permissions for this URI.
                 int flags = View.DRAG_FLAG_GLOBAL | View.DRAG_FLAG_GLOBAL_URI_READ;

                 // Add an optional clip description that that contains an extra String that is
                 // read out by the target app.
                 final ClipDescription clipDescription = new ClipDescription("", new String[]{
                         getContext().getContentResolver().getType(imageUri)});
                 // Extras are stored within a PersistableBundle.
                 PersistableBundle extras = new PersistableBundle(1);
                 // Add a String that the target app will display.
                 extras.putString(EXTRA_IMAGE_INFO,
                         "Drag Started at " + new Date());
                 clipDescription.setExtras(extras);

                 // The ClipData object describes the object that is being dragged and dropped.
                 final ClipData clipData =
                         new ClipData(clipDescription, new ClipData.Item(imageUri));

                 Log.d(TAG, "Created ClipDescription. Starting drag and drop.");
                 // Start the drag and drop event.
                 return view.startDragAndDrop(clipData, shadowBuilder, null, flags);

             }

         };

         // Use the DragStartHelper to detect drag and drop events and use the OnDragStartListener
         // defined above to start the event when it has been detected.
         DragStartHelper helper = new DragStartHelper(imageView, listener);
         helper.attach();
         Log.d(TAG, "DragStartHelper attached to view.");
     }

     /**
      * Copy a drawable resource into local storage and makes it available via the
      * {@link FileProvider}.
      *
      * @see Context#getFilesDir()
      * @see FileProvider
      * @see FileProvider#getUriForFile(Context, String, File)
      */
     private Uri getFileUri(int sourceResourceId, String targetName) {
         // Create the images/ sub directory if it does not exist yet.
         File filePath = new File(getContext().getFilesDir(), "images");
         if (!filePath.exists() && !filePath.mkdir()) {
             return null;
         }

         // Copy a drawable from resources to the internal directory.
         File newFile = new File(filePath, targetName);
         if (!newFile.exists()) {
             copyImageResourceToFile(sourceResourceId, newFile);
         }

         // Make the file accessible via the FileProvider and retrieve its URI.
         return FileProvider.getUriForFile(getContext(), CONTENT_AUTHORITY, newFile);
     }


     /**
      * Copy a PNG resource drawable to a {@File}.
      */
     private void copyImageResourceToFile(int resourceId, File filePath) {
         Bitmap image = BitmapFactory.decodeResource(getResources(), resourceId);

         FileOutputStream out = null;
         try {
             out = new FileOutputStream(filePath);
             image.compress(Bitmap.CompressFormat.PNG, 100, out);
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             try {
                 if (out != null) {
                     out.close();
                 }
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

 }
	/*
	* Copyright 2015, The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.example.android.dragsource;

	import com.example.android.common.logger.Log;

	import android.content.ClipData;
	import android.content.ClipDescription;
	import android.content.Context;
	import android.graphics.Bitmap;
	import android.graphics.BitmapFactory;
	import android.graphics.Point;
	import android.net.Uri;
	import android.os.Bundle;
	import android.os.PersistableBundle;
	import android.support.annotation.Nullable;
	import android.support.v13.view.DragStartHelper;
	import android.support.v4.app.Fragment;
	import android.support.v4.content.FileProvider;
	import android.view.DragEvent;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.ImageView;

	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.util.Date;


	/**
	* This sample demonstrates data can be moved between views within the app or between different
	* apps via drag and drop.
	* <p>This is the source app for the drag and drop sample. This app contains several
	* {@link android.widget.ImageView} widgets which can be a drag source. Images can be dropped
	* to a drop target area within the same app or in the DropTarget app (a separate app in this
	* sample).
	* <p>
	* There is also one {@link android.widget.EditText} widget that can be a drag source (no extra
	* setup is necessary).
	* <p/>
	* To enable cross application drag and drop, the {@link android.view.View#DRAG_FLAG_GLOBAL}
	* permission needs to be passed to the {@link android.view.View#startDragAndDrop(ClipData,
	* View.DragShadowBuilder, Object, int)} method. If a Uri
	* requiring permission grants is being sent, then the
	* {@link android.view.View#DRAG_FLAG_GLOBAL_URI_READ} and/or the
	* {@link android.view.View#DRAG_FLAG_GLOBAL_URI_WRITE} flags must be used also.
	*/
	public class DragSourceFragment extends Fragment {

	/**
	* Name of saved data that stores the dropped image URI on the local ImageView when set.
	*/
	private static final String IMAGE_URI = "IMAGE_URI";

	/**
	* Name of the parameter for a {@link ClipData} extra that stores a text describing the dragged
	* image.
	*/
	public static final String EXTRA_IMAGE_INFO = "IMAGE_INFO";

	/**
	* Uri of the ImageView source when set.
	*/
	private Uri mLocalImageUri;

	private static final String TAG = "DragSourceFragment";

	private static final String CONTENT_AUTHORITY = "com.example.android.dragsource.fileprovider";

	@Nullable
	@Override
	public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
	@Nullable Bundle savedInstanceState) {

	View view = inflater.inflate(R.layout.fragment_dragsource, null);

	// Set up two image views for global drag and drop with a permission grant.
	Uri imageUri = getFileUri(R.drawable.image1, "image1.png");
	ImageView imageView = (ImageView) view.findViewById(R.id.image_one);
	setUpDraggableImage(imageView, imageUri);
	imageView.setImageURI(imageUri);

	imageUri = getFileUri(R.drawable.image2, "image2.png");
	imageView = (ImageView) view.findViewById(R.id.image_two);
	setUpDraggableImage(imageView, imageUri);
	imageView.setImageURI(imageUri);

	// Set up the local drop target area.
	final ImageView localImageTarget = (ImageView) view.findViewById(R.id.local_target);
	localImageTarget.setOnDragListener(new ImageDragListener() {
	@Override
	protected boolean setImageUri(View view, DragEvent event, Uri uri) {
	mLocalImageUri = uri;
	Log.d(TAG, "Setting local image to: " + uri);
	return super.setImageUri(view, event, uri);
	}
	});

	if (savedInstanceState != null) {
	final String uriString = savedInstanceState.getString(IMAGE_URI);
	if (uriString != null) {
	mLocalImageUri = Uri.parse(uriString);
	Log.d(TAG, "Restoring local image to: " + mLocalImageUri);
	localImageTarget.setImageURI(mLocalImageUri);
	}
	}
	return view;
	}

	@Override
	public void onSaveInstanceState(Bundle savedInstanceState) {
	if (mLocalImageUri != null) {
	savedInstanceState.putString(IMAGE_URI, mLocalImageUri.toString());
	}
	super.onSaveInstanceState(savedInstanceState);
	}

	private void setUpDraggableImage(ImageView imageView, final Uri imageUri) {

	// Set up a listener that starts the drag and drop event with flags and extra data.
	DragStartHelper.OnDragStartListener listener = new DragStartHelper.OnDragStartListener() {
	@Override
	public boolean onDragStart(View view, final DragStartHelper helper) {
	Log.d(TAG, "Drag start event received from helper.");

	// Use a DragShadowBuilder
	View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view) {
	@Override
	public void onProvideShadowMetrics(Point shadowSize, Point shadowTouchPoint) {
	super.onProvideShadowMetrics(shadowSize, shadowTouchPoint);
	// Notify the DragStartHelper of point where the view was touched.
	helper.getTouchPosition(shadowTouchPoint);
	Log.d(TAG, "View was touched at: " + shadowTouchPoint);
	}
	};

	// Set up the flags for the drag event.
	// Enable drag and drop across apps (global)
	// and require read permissions for this URI.
	int flags = View.DRAG_FLAG_GLOBAL \| View.DRAG_FLAG_GLOBAL_URI_READ;

	// Add an optional clip description that that contains an extra String that is
	// read out by the target app.
	final ClipDescription clipDescription = new ClipDescription("", new String[]{
	getContext().getContentResolver().getType(imageUri)});
	// Extras are stored within a PersistableBundle.
	PersistableBundle extras = new PersistableBundle(1);
	// Add a String that the target app will display.
	extras.putString(EXTRA_IMAGE_INFO,
	"Drag Started at " + new Date());
	clipDescription.setExtras(extras);

	// The ClipData object describes the object that is being dragged and dropped.
	final ClipData clipData =
	new ClipData(clipDescription, new ClipData.Item(imageUri));

	Log.d(TAG, "Created ClipDescription. Starting drag and drop.");
	// Start the drag and drop event.
	return view.startDragAndDrop(clipData, shadowBuilder, null, flags);

	}

	};

	// Use the DragStartHelper to detect drag and drop events and use the OnDragStartListener
	// defined above to start the event when it has been detected.
	DragStartHelper helper = new DragStartHelper(imageView, listener);
	helper.attach();
	Log.d(TAG, "DragStartHelper attached to view.");
	}

	/**
	* Copy a drawable resource into local storage and makes it available via the
	* {@link FileProvider}.
	*
	* @see Context#getFilesDir()
	* @see FileProvider
	* @see FileProvider#getUriForFile(Context, String, File)
	*/
	private Uri getFileUri(int sourceResourceId, String targetName) {
	// Create the images/ sub directory if it does not exist yet.
	File filePath = new File(getContext().getFilesDir(), "images");
	if (!filePath.exists() && !filePath.mkdir()) {
	return null;
	}

	// Copy a drawable from resources to the internal directory.
	File newFile = new File(filePath, targetName);
	if (!newFile.exists()) {
	copyImageResourceToFile(sourceResourceId, newFile);
	}

	// Make the file accessible via the FileProvider and retrieve its URI.
	return FileProvider.getUriForFile(getContext(), CONTENT_AUTHORITY, newFile);
	}


	/**
	* Copy a PNG resource drawable to a {@File}.
	*/
	private void copyImageResourceToFile(int resourceId, File filePath) {
	Bitmap image = BitmapFactory.decodeResource(getResources(), resourceId);

	FileOutputStream out = null;
	try {
	out = new FileOutputStream(filePath);
	image.compress(Bitmap.CompressFormat.PNG, 100, out);
	} catch (Exception e) {
	e.printStackTrace();
	} finally {
	try {
	if (out != null) {
	out.close();
	}
	} catch (IOException e) {
	e.printStackTrace();
	}
	}
	}

	}