root/ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java

DEFINITIONS

1. JNINamespace
2. selectFile
3. getFileForImageCapture
4. resolveFileName
5. onIntentCompleted
6. onFileNotSelected
7. noSpecificType
8. shouldShowTypes
9. shouldShowImageTypes
10. shouldShowVideoTypes
11. shouldShowAudioTypes
12. acceptsSpecificType
13. captureCamera
14. captureCamcorder
15. captureMicrophone
16. acceptSpecificType
17. create
18. nativeOnFileSelected
19. nativeOnFileNotSelected

// Copyright 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.

package org.chromium.ui.base;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.text.TextUtils;

import org.chromium.base.CalledByNative;
import org.chromium.base.JNINamespace;
import org.chromium.ui.R;

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * A dialog that is triggered from a file input field that allows a user to select a file based on
 * a set of accepted file types. The path of the selected file is passed to the native dialog.
 */
@JNINamespace("ui")
class SelectFileDialog implements WindowAndroid.IntentCallback{
    private static final String IMAGE_TYPE = "image/";
    private static final String VIDEO_TYPE = "video/";
    private static final String AUDIO_TYPE = "audio/";
    private static final String ALL_IMAGE_TYPES = IMAGE_TYPE + "*";
    private static final String ALL_VIDEO_TYPES = VIDEO_TYPE + "*";
    private static final String ALL_AUDIO_TYPES = AUDIO_TYPE + "*";
    private static final String ANY_TYPES = "*/*";
    private static final String CAPTURE_IMAGE_DIRECTORY = "browser-photos";

    private final long mNativeSelectFileDialog;
    private List<String> mFileTypes;
    private boolean mCapture;
    private Uri mCameraOutputUri;

    private SelectFileDialog(long nativeSelectFileDialog) {
        mNativeSelectFileDialog = nativeSelectFileDialog;
    }

    /**
     * Creates and starts an intent based on the passed fileTypes and capture value.
     * @param fileTypes MIME types requested (i.e. "image/*")
     * @param capture The capture value as described in http://www.w3.org/TR/html-media-capture/
     * @param window The WindowAndroid that can show intents
     */
    @CalledByNative
    private void selectFile(String[] fileTypes, boolean capture, WindowAndroid window) {
        mFileTypes = new ArrayList<String>(Arrays.asList(fileTypes));
        mCapture = capture;

        Intent chooser = new Intent(Intent.ACTION_CHOOSER);
        Intent camera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        mCameraOutputUri = Uri.fromFile(getFileForImageCapture());
        camera.putExtra(MediaStore.EXTRA_OUTPUT, mCameraOutputUri);
        Intent camcorder = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
        Intent soundRecorder = new Intent(
                MediaStore.Audio.Media.RECORD_SOUND_ACTION);

        // Quick check - if the |capture| parameter is set and |fileTypes| has the appropriate MIME
        // type, we should just launch the appropriate intent. Otherwise build up a chooser based on
        // the accept type and then display that to the user.
        if (captureCamera()) {
            if (window.showIntent(camera, this, R.string.low_memory_error)) return;
        } else if (captureCamcorder()) {
            if (window.showIntent(camcorder, this, R.string.low_memory_error)) return;
        } else if (captureMicrophone()) {
            if (window.showIntent(soundRecorder, this, R.string.low_memory_error)) return;
        }

        Intent getContentIntent = new Intent(Intent.ACTION_GET_CONTENT);
        getContentIntent.addCategory(Intent.CATEGORY_OPENABLE);
        ArrayList<Intent> extraIntents = new ArrayList<Intent>();
        if (!noSpecificType()) {
            // Create a chooser based on the accept type that was specified in the webpage. Note
            // that if the web page specified multiple accept types, we will have built a generic
            // chooser above.
            if (shouldShowImageTypes()) {
                extraIntents.add(camera);
                getContentIntent.setType(ALL_IMAGE_TYPES);
            } else if (shouldShowVideoTypes()) {
                extraIntents.add(camcorder);
                getContentIntent.setType(ALL_VIDEO_TYPES);
            } else if (shouldShowAudioTypes()) {
                extraIntents.add(soundRecorder);
                getContentIntent.setType(ALL_AUDIO_TYPES);
            }
        }

        if (extraIntents.isEmpty()) {
            // We couldn't resolve an accept type, so fallback to a generic chooser.
            getContentIntent.setType(ANY_TYPES);
            extraIntents.add(camera);
            extraIntents.add(camcorder);
            extraIntents.add(soundRecorder);
        }

        chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS,
                extraIntents.toArray(new Intent[] { }));

        chooser.putExtra(Intent.EXTRA_INTENT, getContentIntent);

        if (!window.showIntent(chooser, this, R.string.low_memory_error)) {
            onFileNotSelected();
        }
    }

    /**
     * Get a file for the image capture in the CAPTURE_IMAGE_DIRECTORY directory.
     */
    private File getFileForImageCapture() {
        File externalDataDir = Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_DCIM);
        File cameraDataDir = new File(externalDataDir.getAbsolutePath() +
                File.separator + CAPTURE_IMAGE_DIRECTORY);
        if (!cameraDataDir.exists() && !cameraDataDir.mkdirs()) {
            cameraDataDir = externalDataDir;
        }
        File photoFile = new File(cameraDataDir.getAbsolutePath() +
                File.separator + System.currentTimeMillis() + ".jpg");
        return photoFile;
    }

    /**
     * @return the display name of the @code uri if present in the database
     *  or an empty string otherwise.
     */
    private String resolveFileName(Uri uri, ContentResolver contentResolver) {
        if (contentResolver == null || uri == null) return "";
        Cursor cursor = null;
        try {
            cursor = contentResolver.query(uri, null, null, null, null);

            if (cursor != null && cursor.getCount() >= 1) {
                cursor.moveToFirst();
                int index = cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME);
                if (index > -1) return cursor.getString(index);
            }
        } catch (NullPointerException e) {
            // Some android models don't handle the provider call correctly.
            // see crbug.com/345393
            return "";
        } finally {
            if (cursor != null) cursor.close();
        }
        return "";
    }

    /**
     * Callback method to handle the intent results and pass on the path to the native
     * SelectFileDialog.
     * @param window The window that has access to the application activity.
     * @param resultCode The result code whether the intent returned successfully.
     * @param contentResolver The content resolver used to extract the path of the selected file.
     * @param results The results of the requested intent.
     */
    @Override
    public void onIntentCompleted(WindowAndroid window, int resultCode,
            ContentResolver contentResolver, Intent results) {
        if (resultCode != Activity.RESULT_OK) {
            onFileNotSelected();
            return;
        }

        if (results == null) {
            // If we have a successful return but no data, then assume this is the camera returning
            // the photo that we requested.
            nativeOnFileSelected(mNativeSelectFileDialog, mCameraOutputUri.getPath(), "");

            // Broadcast to the media scanner that there's a new photo on the device so it will
            // show up right away in the gallery (rather than waiting until the next time the media
            // scanner runs).
            window.sendBroadcast(new Intent(
                    Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, mCameraOutputUri));
            return;
        }

        if (ContentResolver.SCHEME_FILE.equals(results.getData().getScheme())) {
            nativeOnFileSelected(mNativeSelectFileDialog,
                    results.getData().getSchemeSpecificPart(), "");
            return;
        }

        if (ContentResolver.SCHEME_CONTENT.equals(results.getScheme())) {
            nativeOnFileSelected(mNativeSelectFileDialog,
                                 results.getData().toString(),
                                 resolveFileName(results.getData(),
                                                 contentResolver));
            return;
        }

        onFileNotSelected();
        window.showError(R.string.opening_file_error);
    }

    private void onFileNotSelected() {
        nativeOnFileNotSelected(mNativeSelectFileDialog);
    }

    private boolean noSpecificType() {
        // We use a single Intent to decide the type of the file chooser we display to the user,
        // which means we can only give it a single type. If there are multiple accept types
        // specified, we will fallback to a generic chooser (unless a capture parameter has been
        // specified, in which case we'll try to satisfy that first.
        return mFileTypes.size() != 1 || mFileTypes.contains(ANY_TYPES);
    }

    private boolean shouldShowTypes(String allTypes, String specificType) {
        if (noSpecificType() || mFileTypes.contains(allTypes)) return true;
        return acceptSpecificType(specificType);
    }

    private boolean shouldShowImageTypes() {
        return shouldShowTypes(ALL_IMAGE_TYPES, IMAGE_TYPE);
    }

    private boolean shouldShowVideoTypes() {
        return shouldShowTypes(ALL_VIDEO_TYPES, VIDEO_TYPE);
    }

    private boolean shouldShowAudioTypes() {
        return shouldShowTypes(ALL_AUDIO_TYPES, AUDIO_TYPE);
    }

    private boolean acceptsSpecificType(String type) {
        return mFileTypes.size() == 1 && TextUtils.equals(mFileTypes.get(0), type);
    }

    private boolean captureCamera() {
        return mCapture && acceptsSpecificType(ALL_IMAGE_TYPES);
    }

    private boolean captureCamcorder() {
        return mCapture && acceptsSpecificType(ALL_VIDEO_TYPES);
    }

    private boolean captureMicrophone() {
        return mCapture && acceptsSpecificType(ALL_AUDIO_TYPES);
    }

    private boolean acceptSpecificType(String accept) {
        for (String type : mFileTypes) {
            if (type.startsWith(accept)) {
                return true;
            }
        }
        return false;
    }

    @CalledByNative
    private static SelectFileDialog create(long nativeSelectFileDialog) {
        return new SelectFileDialog(nativeSelectFileDialog);
    }

    private native void nativeOnFileSelected(long nativeSelectFileDialogImpl,
            String filePath, String displayName);
    private native void nativeOnFileNotSelected(long nativeSelectFileDialogImpl);
}