WeakHandler (gfycat-common API)

java.lang.Object
- com.gfycat.common.weakhandler.WeakHandler

```
public class WeakHandler
extends java.lang.Object
```
Memory safer implementation of android.os.Handler
Original implementation of Handlers always keeps hard reference to handler in queue of execution. If you create anonymous handler and post delayed message into it, it will keep all parent class for that time in memory even if it could be cleaned.
This implementation is trickier, it will keep WeakReferences to runnables and messages, and GC could collect them once WeakHandler instance is not referenced any more

See Also:

Created by Dmytro Voronkevych on 17/06/2014.

Constructor Summary

Constructors
Constructor and Description
`WeakHandler()` Default constructor associates this handler with the `Looper` for the current thread.
`WeakHandler(android.os.Handler.Callback callback)` Constructor associates this handler with the `Looper` for the current thread and takes a callback interface in which you can handle messages.
`WeakHandler(android.os.Looper looper)` Use the provided `Looper` instead of the default one.
`WeakHandler(android.os.Looper looper, android.os.Handler.Callback callback)` Use the provided `Looper` instead of the default one and take a callback interface in which to handle messages.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`android.os.Looper`	`getLooper()`
`boolean`	`hasMessages(int what)` Check if there are any pending posts of messages with code 'what' in the message queue.
`boolean`	`hasMessages(int what, java.lang.Object object)` Check if there are any pending posts of messages with code 'what' and whose obj is 'object' in the message queue.
`boolean`	`post(java.lang.Runnable r)` Causes the Runnable r to be added to the message queue.
`boolean`	`postAtFrontOfQueue(java.lang.Runnable r)` Posts a message to an object that implements Runnable.
`boolean`	`postAtTime(java.lang.Runnable r, long uptimeMillis)` Causes the Runnable r to be added to the message queue, to be run at a specific time given by `uptimeMillis`.
`boolean`	`postAtTime(java.lang.Runnable r, java.lang.Object token, long uptimeMillis)` Causes the Runnable r to be added to the message queue, to be run at a specific time given by `uptimeMillis`.
`boolean`	`postDelayed(java.lang.Runnable r, long delayMillis)` Causes the Runnable r to be added to the message queue, to be run after the specified amount of time elapses.
`void`	`removeCallbacks(java.lang.Runnable r)` Remove any pending posts of Runnable r that are in the message queue.
`void`	`removeCallbacks(java.lang.Runnable r, java.lang.Object token)` Remove any pending posts of Runnable `r` with Object `token` that are in the message queue.
`void`	`removeCallbacksAndMessages(java.lang.Object token)` Remove any pending posts of callbacks and sent messages whose `obj` is `token`.
`void`	`removeMessages(int what)` Remove any pending posts of messages with code 'what' that are in the message queue.
`void`	`removeMessages(int what, java.lang.Object object)` Remove any pending posts of messages with code 'what' and whose obj is 'object' that are in the message queue.
`boolean`	`sendEmptyMessage(int what)` Sends a Message containing only the what value.
`boolean`	`sendEmptyMessageAtTime(int what, long uptimeMillis)` Sends a Message containing only the what value, to be delivered at a specific time.
`boolean`	`sendEmptyMessageDelayed(int what, long delayMillis)` Sends a Message containing only the what value, to be delivered after the specified amount of time elapses.
`boolean`	`sendMessage(android.os.Message msg)` Pushes a message onto the end of the message queue after all pending messages before the current time.
`boolean`	`sendMessageAtFrontOfQueue(android.os.Message msg)` Enqueue a message at the front of the message queue, to be processed on the next iteration of the message loop.
`boolean`	`sendMessageAtTime(android.os.Message msg, long uptimeMillis)` Enqueue a message into the message queue after all pending messages before the absolute time (in milliseconds) `uptimeMillis`.
`boolean`	`sendMessageDelayed(android.os.Message msg, long delayMillis)` Enqueue a message into the message queue after all pending messages before (current time + delayMillis).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - WeakHandler
```
public WeakHandler()
```
    Default constructor associates this handler with the Looper for the current thread.
    If this thread does not have a looper, this handler won't be able to receive messages so an exception is thrown.
  - WeakHandler
```
public WeakHandler(android.os.Handler.Callback callback)
```
    Constructor associates this handler with the Looper for the current thread and takes a callback interface in which you can handle messages.
    If this thread does not have a looper, this handler won't be able to receive messages so an exception is thrown.
    
    Parameters:
    
    callback - The callback interface in which to handle messages, or null.
  - WeakHandler
```
public WeakHandler(android.os.Looper looper)
```
    Use the provided Looper instead of the default one.
    
    Parameters:
    
    looper - The looper, must not be null.
  - WeakHandler
```
public WeakHandler(android.os.Looper looper,
                   android.os.Handler.Callback callback)
```
    Use the provided Looper instead of the default one and take a callback interface in which to handle messages.
    
    Parameters:
    
    looper - The looper, must not be null.
    
    callback - The callback interface in which to handle messages, or null.
- Method Detail
  - post
```
public final boolean post(java.lang.Runnable r)
```
    Causes the Runnable r to be added to the message queue. The runnable will be run on the thread to which this handler is attached.
    
    Parameters:
    
    r - The Runnable that will be executed.
    
    Returns:
    
    Returns true if the Runnable was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
  - postAtTime
```
public final boolean postAtTime(java.lang.Runnable r,
                                long uptimeMillis)
```
    Causes the Runnable r to be added to the message queue, to be run at a specific time given by uptimeMillis. The time-base is SystemClock.uptimeMillis(). The runnable will be run on the thread to which this handler is attached.
    
    Parameters:
    
    r - The Runnable that will be executed.
    
    uptimeMillis - The absolute time at which the callback should run, using the SystemClock.uptimeMillis() time-base.
    
    Returns:
    
    Returns true if the Runnable was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting. Note that a result of true does not mean the Runnable will be processed -- if the looper is quit before the delivery time of the message occurs then the message will be dropped.
  - postAtTime
```
public final boolean postAtTime(java.lang.Runnable r,
                                java.lang.Object token,
                                long uptimeMillis)
```
    Causes the Runnable r to be added to the message queue, to be run at a specific time given by uptimeMillis. The time-base is SystemClock.uptimeMillis(). The runnable will be run on the thread to which this handler is attached.
    
    Parameters:
    
    r - The Runnable that will be executed.
    
    uptimeMillis - The absolute time at which the callback should run, using the SystemClock.uptimeMillis() time-base.
    
    Returns:
    
    Returns true if the Runnable was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting. Note that a result of true does not mean the Runnable will be processed -- if the looper is quit before the delivery time of the message occurs then the message will be dropped.
    
    See Also:
    
    SystemClock.uptimeMillis()
  - postDelayed
```
public final boolean postDelayed(java.lang.Runnable r,
                                 long delayMillis)
```
    Causes the Runnable r to be added to the message queue, to be run after the specified amount of time elapses. The runnable will be run on the thread to which this handler is attached.
    
    Parameters:
    
    r - The Runnable that will be executed.
    
    delayMillis - The delay (in milliseconds) until the Runnable will be executed.
    
    Returns:
    
    Returns true if the Runnable was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting. Note that a result of true does not mean the Runnable will be processed -- if the looper is quit before the delivery time of the message occurs then the message will be dropped.
  - postAtFrontOfQueue
```
public final boolean postAtFrontOfQueue(java.lang.Runnable r)
```
    Posts a message to an object that implements Runnable. Causes the Runnable r to executed on the next iteration through the message queue. The runnable will be run on the thread to which this handler is attached. This method is only for use in very special circumstances -- it can easily starve the message queue, cause ordering problems, or have other unexpected side-effects.
    
    Parameters:
    
    r - The Runnable that will be executed.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
  - removeCallbacks
```
public final void removeCallbacks(java.lang.Runnable r)
```
    Remove any pending posts of Runnable r that are in the message queue.
  - removeCallbacks
```
public final void removeCallbacks(java.lang.Runnable r,
                                  java.lang.Object token)
```
    Remove any pending posts of Runnable r with Object token that are in the message queue. If token is null, all callbacks will be removed.
  - sendMessage
```
public final boolean sendMessage(android.os.Message msg)
```
    Pushes a message onto the end of the message queue after all pending messages before the current time. It will be received in callback, in the thread attached to this handler.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
  - sendEmptyMessage
```
public final boolean sendEmptyMessage(int what)
```
    Sends a Message containing only the what value.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
  - sendEmptyMessageDelayed
```
public final boolean sendEmptyMessageDelayed(int what,
                                             long delayMillis)
```
    Sends a Message containing only the what value, to be delivered after the specified amount of time elapses.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
    
    See Also:
    
    sendMessageDelayed(Message, long)
  - sendEmptyMessageAtTime
```
public final boolean sendEmptyMessageAtTime(int what,
                                            long uptimeMillis)
```
    Sends a Message containing only the what value, to be delivered at a specific time.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
    
    See Also:
    
    sendMessageAtTime(Message, long)
  - sendMessageDelayed
```
public final boolean sendMessageDelayed(android.os.Message msg,
                                        long delayMillis)
```
    Enqueue a message into the message queue after all pending messages before (current time + delayMillis). You will receive it in callback, in the thread attached to this handler.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting. Note that a result of true does not mean the message will be processed -- if the looper is quit before the delivery time of the message occurs then the message will be dropped.
  - sendMessageAtTime
```
public boolean sendMessageAtTime(android.os.Message msg,
                                 long uptimeMillis)
```
    Enqueue a message into the message queue after all pending messages before the absolute time (in milliseconds) uptimeMillis. The time-base is SystemClock.uptimeMillis(). You will receive it in callback, in the thread attached to this handler.
    
    Parameters:
    
    uptimeMillis - The absolute time at which the message should be delivered, using the SystemClock.uptimeMillis() time-base.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting. Note that a result of true does not mean the message will be processed -- if the looper is quit before the delivery time of the message occurs then the message will be dropped.
  - sendMessageAtFrontOfQueue
```
public final boolean sendMessageAtFrontOfQueue(android.os.Message msg)
```
    Enqueue a message at the front of the message queue, to be processed on the next iteration of the message loop. You will receive it in callback, in the thread attached to this handler. This method is only for use in very special circumstances -- it can easily starve the message queue, cause ordering problems, or have other unexpected side-effects.
    
    Returns:
    
    Returns true if the message was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting.
  - removeMessages
```
public final void removeMessages(int what)
```
    Remove any pending posts of messages with code 'what' that are in the message queue.
  - removeMessages
```
public final void removeMessages(int what,
                                 java.lang.Object object)
```
    Remove any pending posts of messages with code 'what' and whose obj is 'object' that are in the message queue. If object is null, all messages will be removed.
  - removeCallbacksAndMessages
```
public final void removeCallbacksAndMessages(java.lang.Object token)
```
    Remove any pending posts of callbacks and sent messages whose obj is token. If token is null, all callbacks and messages will be removed.
  - hasMessages
```
public final boolean hasMessages(int what)
```
    Check if there are any pending posts of messages with code 'what' in the message queue.
  - hasMessages
```
public final boolean hasMessages(int what,
                                 java.lang.Object object)
```
    Check if there are any pending posts of messages with code 'what' and whose obj is 'object' in the message queue.
  - getLooper
```
public final android.os.Looper getLooper()
```

Class WeakHandler

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

WeakHandler

WeakHandler

WeakHandler

WeakHandler

Method Detail

post

postAtTime

postAtTime

postDelayed

postAtFrontOfQueue

removeCallbacks

removeCallbacks

sendMessage

sendEmptyMessage

sendEmptyMessageDelayed

sendEmptyMessageAtTime

sendMessageDelayed

sendMessageAtTime

sendMessageAtFrontOfQueue

removeMessages

removeMessages

removeCallbacksAndMessages

hasMessages

hasMessages

getLooper