DropHelper
public final class DropHelper
Helper class used to configure Views to receive data dropped by a drag and drop operation. Includes support for content insertion using an OnReceiveContentListener. Adds highlighting during the drag interaction to indicate to the user where the drop action can successfully take place.
To ensure that drop target highlighting and text data handling work correctly, all EditText elements in the drop target view's descendant tree (that is, any EditText elements contained within the drop target) must be provided as arguments to a call to addInnerEditTexts. Otherwise, an EditText within the target will steal the focus during the drag and drop operation, possibly causing undesired highlighting behavior.
Also, if the user is dragging text data and URI data in the drag and drop ClipData, one of the EditText elements in the drop target is automatically chosen to handle the text data. See addInnerEditTexts for the order of precedence in selecting the EditText that handles the text data.
This helper attaches an OnReceiveContentListener to drop targets and configures drop targets to listen for drag and drop events (see configureView). Do not attach an OnDragListener or additional OnReceiveContentLister to drop targets when using DropHelper.
Note: This class requires Android API level 24 or higher.
Summary
Nested types |
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public final class DropHelper.OptionsOptions for configuring drop targets specified by |
public final class DropHelper.Options.BuilderBuilder for constructing a |
Public methods |
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static void |
configureView(Configures a |
static void |
configureView(Configures a |
Public methods
configureView
public static void configureView(
@NonNull Activity activity,
@NonNull View dropTarget,
@NonNull String[] mimeTypes,
@NonNull OnReceiveContentListener onReceiveContentListener
)
Configures a View for drag and drop operations, including the highlighting that indicates the view is a drop target. Sets a listener that enables the view to handle dropped data.
Same as configureView
Note: If the drop target contains EditText elements, you must use configureView. The Options argument enables you to specify a list of the EditText elements (see addInnerEditTexts).
| Parameters | |
|---|---|
@NonNull Activity activity |
The current |
@NonNull View dropTarget |
A |
@NonNull String[] mimeTypes |
The MIME types the drop target can accept from the dropped data. |
@NonNull OnReceiveContentListener onReceiveContentListener |
A listener that handles the dropped data. |
configureView
public static void configureView(
@NonNull Activity activity,
@NonNull View dropTarget,
@NonNull String[] mimeTypes,
@NonNull DropHelper.Options options,
@NonNull OnReceiveContentListener onReceiveContentListener
)
Configures a View for drag and drop operations, including the highlighting that indicates the view is a drop target. Sets a listener that enables the view to handle dropped data.
If the drop target's view hierarchy contains any EditText elements, they all must be specified in options (see addInnerEditTexts).
View highlighting occurs for a drag action only if a MIME type in the ClipDescription matches a MIME type provided in mimeTypes; wildcards are allowed (for example, "image/*"). A drop can be executed and passed on to the OnReceiveContentListener even if the MIME type is not matched.
See DropHelper for more information.
| Parameters | |
|---|---|
@NonNull Activity activity |
The current |
@NonNull View dropTarget |
A |
@NonNull String[] mimeTypes |
The MIME types the drop target can accept from the dropped data. |
@NonNull DropHelper.Options options |
Configuration options for the drop target (see |
@NonNull OnReceiveContentListener onReceiveContentListener |
A listener that handles the dropped data. |