Code example for PowerManager

Methods: newWakeLock, setBacklightBrightness

1
     *  
     * @throws Exception 
     */ 
    @MediumTest 
    public void testNewWakeLock() throws Exception { 
        PowerManager.WakeLock wl = mPm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "FULL_WAKE_LOCK");
        doTestWakeLock(wl);
 
        wl = mPm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, "SCREEN_BRIGHT_WAKE_LOCK");
        doTestWakeLock(wl);
 
        wl = mPm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "SCREEN_DIM_WAKE_LOCK");
        doTestWakeLock(wl);
 
        wl = mPm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "PARTIAL_WAKE_LOCK");
        doTestWakeLock(wl);
         
        doTestSetBacklightBrightness(); 
 
        // TODO: Some sort of functional test (maybe not in the unit test here?)  
        // that confirms that things are really happening e.g. screen power, keyboard power. 
} 
     
    /** 
     * Confirm that we can't create dysfunctional wakelocks. 
     *  
     * @throws Exception 
     */ 
    @MediumTest 
    public void testBadNewWakeLock() throws Exception { 
         
        final int badFlags = PowerManager.SCREEN_BRIGHT_WAKE_LOCK 
                            | PowerManager.SCREEN_DIM_WAKE_LOCK;
        // wrap in try because we want the error here 
        try { 
            PowerManager.WakeLock wl = mPm.newWakeLock(badFlags, "foo");
        } catch (IllegalArgumentException e) {
            return; 
        } 
        fail("Bad WakeLock flag was not caught.");
    } 
     
    /** 
     * Apply a few tests to a wakelock to make sure it's healthy. 
     *  
     * @param wl The wakelock to be tested. 
     */ 
    private void doTestWakeLock(PowerManager.WakeLock wl) {
        // First try simple acquire/release 
        wl.acquire();
        assertTrue(wl.isHeld());
        wl.release();
        assertFalse(wl.isHeld());
         
        // Try ref-counted acquire/release 
        wl.setReferenceCounted(true);
        wl.acquire();
        assertTrue(wl.isHeld());
        wl.acquire();
        assertTrue(wl.isHeld());
        wl.release();
        assertTrue(wl.isHeld());
        wl.release();
        assertFalse(wl.isHeld());
         
        // Try non-ref-counted 
        wl.setReferenceCounted(false);
        wl.acquire();
        assertTrue(wl.isHeld());
        wl.acquire();
        assertTrue(wl.isHeld());
        wl.release();
        assertFalse(wl.isHeld());
         
        // TODO: Threaded test (needs handler) to make sure timed wakelocks work too 
    } 
     
  
    /** 
     * Test that calling {@link android.os.IHardwareService#setBacklights(int)} requires 
     * permissions. 
     * <p>Tests permission: 
     *   {@link android.Manifest.permission#DEVICE_POWER} 
     */ 
    private void doTestSetBacklightBrightness() { 
        try { 
            mPm.setBacklightBrightness(0);
            fail("setBacklights did not throw SecurityException as expected");
        } catch (SecurityException e) {
            // expected 
        } 
    }