Example usage for android.os FileObserver FileObserver

Introduction

In this page you can find the example usage for android.os FileObserver FileObserver.

Prototype

public FileObserver(String path) 

Source Link

Document

Equivalent to FileObserver(path, FileObserver.ALL_EVENTS).

Usage

From source file:com.sat.sonata.MenuActivity.java

private void processPictureWhenReady(final String picturePath) {
    final File pictureFile = new File(picturePath);

    if (pictureFile.exists()) {
        // The picture is ready; process it.
    } else {//from  w  w  w  .  j a v  a 2s  .co  m
        // The file does not exist yet. Before starting the file observer, you
        // can update your UI to let the user know that the application is
        // waiting for the picture (for example, by displaying the thumbnail
        // image and a progress indicator).

        final File parentDirectory = pictureFile.getParentFile();
        FileObserver observer = new FileObserver(parentDirectory.getPath()) {
            // Protect against additional pending events after CLOSE_WRITE is
            // handled.
            private boolean isFileWritten;

            @Override
            public void onEvent(int event, String path) {
                if (!isFileWritten) {
                    // For safety, make sure that the file that was created in
                    // the directory is actually the one that we're expecting.
                    File affectedFile = new File(parentDirectory, path);
                    isFileWritten = (event == FileObserver.CLOSE_WRITE && affectedFile.equals(pictureFile));

                    if (isFileWritten) {
                        stopWatching();

                        // Now that the file is ready, recursively call
                        // processPictureWhenReady again (on the UI thread).
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                processPictureWhenReady(picturePath);
                            }
                        });
                    }
                }
            }
        };
        observer.startWatching();
    }
}

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