WindowView

Window as in windowsill.

An Android ImageView that can be panned around by tilting your device, as if you were looking through a window.

Usage

Add it to your project using Gradle:

compile 'com.jmedeisis:windowview:0.2.0'

Use in place of an ImageView. Example XML layout file:

<com.jmedeisis.windowview.WindowView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@drawable/my_image" />

Please refer to the included sample application project for a complete example.

Configuration

You will typically want to configure the following attributes for the WindowView class:

• wwv_max_pitch - maximum angle (in degrees) from origin for vertical device tilts. Default - 30°

• wwv_max_roll - maximum angle (in degrees) from origin for horizontal device tilts. Default - 30°

• wwv_vertical_origin - (in degrees) when device pitch equals this value, the image is centered vertically. Default - 0°

• wwv_horizontal_origin - (in degrees) when device roll equals this value, the image is centered horizontally. Default - 0°

You may also want to configure more advanced attributes:

• wwv_orientation_mode - Absolute or Relative (default). Specifies whether device tilt should be tracked with respect to Absolute world coordinates (i.e. pitch, roll w.r.t. ground plane) or with respect to the device orientation when WindowView is created, which WindowView refers to as the 'orientation origin'. If using the latter, i.e. Relative, you may use WindowView#resetOrientationOrigin(boolean) to set the orientation origin to that of the device when the method is called.

• wwv_translate_mode - Constant or Proportional (default). Specifies how much the image is translated in response to device tilt. If Proportional, the image moves within the full range defined by max_pitch / max_roll, with the extremities of the image visible when device pitch / roll is at those angles. If Constant, the image moves a constant amount per unit of tilt which is defined by max_constant_translation, achieved when pitch / roll are at max_pitch / max_roll.

• wwv_max_constant_translation - see above. Default - 150dp

• wwv_sensor_sampling_period - the desired rate of sensor events. In microseconds or one of fast, normal (default) or slow. If using microsecond values, higher values result in slower sensor updates. Directly related to the rate at which WindowView updates in response to device tilt.

• wwv_tilt_sensor_mode - Manual or Automatic (default). Specifies whether WindowView is responsible for when tilt motion tracking starts and stops. If Automatic, WindowView works out of the box and requires no extra configuration. If Manual, you must explicitly start and stop tilt motion tracking. You have two options:

  • Use WindowView#startTiltTracking() and WindowView#stopTiltTracking(), e.g. in your Activity's onResume() and onPause(), respectively.

  • Use WindowView#attachTiltTracking(TiltSensor) and WindowView#detachTiltTracking(TiltSensor). This approach is recommended when using multiple WindowViews in a single logical layout. The externally managed TiltSensor should be started and stopped using TiltSensor#startTracking(int) and TiltSensor#stopTracking() as appropriate.

Example configuration:

<com.jmedeisis.windowview.WindowView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@drawable/my_image"
    app:wwv_tilt_sensor_mode="Manual"
    app:wwv_orientation_mode="Relative"
    app:wwv_translate_mode="Constant"
    app:wwv_max_constant_translation="100dp"
    app:wwv_sensor_sampling_period="fast"
    app:wwv_max_pitch="15"
    app:wwv_max_roll="15"
    app:wwv_vertical_origin="0"
    app:wwv_horizontal_origin="0" />

Limitations

• Only supports the CENTER_CROP scale type.
• Works for API levels 9+.

Development

Pull requests are welcome and encouraged for bugfixes and features such as:

• adaptive smoothing filters tuned for different sensor accuracy and rates
• bi-directional image panning

License

WindowView is licensed under the terms of the MIT License.