T
- The specific subclass of view wrapped by this target.Z
- The resource type this target will receive.public abstract class ViewTarget<T extends View,Z> extends BaseTarget<Z>
Target
for loading Bitmap
s into View
s that provides default
implementations for most most methods and can determine the size of views using a
ViewTreeObserver.OnDrawListener
.
To detect View
reuse in ListView
or any ViewGroup
that reuses
views, this class uses the View.setTag(Object)
method to store some metadata so that if a view is reused,
any previous loads or resources from previous loads can be cancelled or reused.
Any calls to View.setTag(Object)
} on a View given to this class will result in excessive allocations and
and/or IllegalArgumentException
s. If you must call View.setTag(Object)
on a view, consider
using BaseTarget
or SimpleTarget
instead.
Modifier and Type | Field and Description |
---|---|
protected T |
view |
SIZE_ORIGINAL
Constructor and Description |
---|
ViewTarget(T view) |
Modifier and Type | Method and Description |
---|---|
Request |
getRequest()
Returns any stored request using
View.getTag() . |
void |
getSize(SizeReadyCallback cb)
Determines the size of the view by first checking
View.getWidth() and
View.getHeight() . |
T |
getView()
Returns the wrapped
View . |
void |
setRequest(Request request)
Stores the request using
View.setTag(Object) . |
static void |
setTagId(int tagId)
Sets the android resource id to use in conjunction with
View.setTag(int, Object)
to store temporary state allowing loads to be automatically cancelled and resources re-used
in scrolling lists. |
String |
toString() |
onDestroy, onLoadCleared, onLoadFailed, onLoadStarted, onStart, onStop
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
onResourceReady
public ViewTarget(T view)
public static void setTagId(int tagId)
View.setTag(int, Object)
to store temporary state allowing loads to be automatically cancelled and resources re-used
in scrolling lists.
If no tag id is set, Glide will use View.setTag(Object)
.
Warning: prior to Android 4.0 tags were stored in a static map. Using this method prior
to Android 4.0 may cause memory leaks and isn't recommended. If you do use this method
on older versions, be sure to call Glide.clear(View)
on any view
you start a load into to ensure that the static state is removed.
tagId
- The android resource to use.public void getSize(SizeReadyCallback cb)
View.getWidth()
and
View.getHeight()
. If one or both are zero, it then checks the view's
ViewGroup.LayoutParams
. If one or both of the params width and height are less than or
equal to zero, it then adds an ViewTreeObserver.OnPreDrawListener
which waits until the view
has been measured before calling the callback with the view's drawn width and height.cb
- The callback that must be called when the size of the target has been determinedpublic void setRequest(Request request)
View.setTag(Object)
.setRequest
in interface Target<Z>
setRequest
in class BaseTarget<Z>
request
- public Request getRequest()
View.getTag()
.
For Glide to function correctly, Glide must be the only thing that calls View.setTag(Object)
. If the
tag is cleared or set to another object type, Glide will not be able to retrieve and cancel previous loads
which will not only prevent Glide from reusing resource, but will also result in incorrect images being
loaded and lots of flashing of images in lists. As a result, this will throw an
IllegalArgumentException
if View.getTag()
} returns a non null object
that is not an Request
.
getRequest
in interface Target<Z>
getRequest
in class BaseTarget<Z>