Package org.eclipse.swt.dnd
Class Transfer
java.lang.Object
org.eclipse.swt.dnd.Transfer
- Direct Known Subclasses:
ByteArrayTransfer
Transfer
provides a mechanism for converting between a java
representation of data and a platform specific representation of data and
vice versa. It is used in data transfer operations such as drag and drop and
clipboard copy/paste.
You should only need to become familiar with this class if you are implementing a Transfer subclass and you are unable to subclass the ByteArrayTransfer class.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract TransferData[]
Returns a list of the platform specific data types that can be converted using this transfer agent.protected abstract int[]
Returns the platform specific ids of the data types that can be converted using this transfer agent.protected abstract String[]
Returns the platform specific names of the data types that can be converted using this transfer agent.abstract boolean
isSupportedType
(TransferData transferData) Returns true if theTransferData
data type can be converted using this transfer agent, or false otherwise (including if transferData isnull
).protected abstract void
javaToNative
(Object object, TransferData transferData) Converts a java representation of data to a platform specific representation of the data.protected abstract Object
nativeToJava
(TransferData transferData) Converts a platform specific representation of data to a java representation.static int
registerType
(String formatName) Registers a name for a data type and returns the associated unique identifier.protected boolean
Test that the object is of the correct format for this Transfer class.
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Constructor Details
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Transfer
public Transfer()
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Method Details
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getSupportedTypes
Returns a list of the platform specific data types that can be converted using this transfer agent.Only the data type fields of the
TransferData
objects are filled in.- Returns:
- a list of the data types that can be converted using this transfer agent
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isSupportedType
Returns true if theTransferData
data type can be converted using this transfer agent, or false otherwise (including if transferData isnull
).- Parameters:
transferData
- a platform specific description of a data type; only the data type fields of theTransferData
object need to be filled in- Returns:
- true if the transferData data type can be converted using this transfer agent
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getTypeIds
protected abstract int[] getTypeIds()Returns the platform specific ids of the data types that can be converted using this transfer agent.- Returns:
- the platform specific ids of the data types that can be converted using this transfer agent
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getTypeNames
Returns the platform specific names of the data types that can be converted using this transfer agent.- Returns:
- the platform specific names of the data types that can be converted using this transfer agent.
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javaToNative
Converts a java representation of data to a platform specific representation of the data.On a successful conversion, the transferData.result field will be set as follows:
- Windows: COM.S_OK
- GTK: 1
If this transfer agent is unable to perform the conversion, the transferData.result field will be set to a failure value as follows:
- Windows: COM.DV_E_TYMED or COM.E_FAIL
- GTK: 0
- Parameters:
object
- a java representation of the data to be converted; the type of Object that is passed in is dependent on theTransfer
subclass.transferData
- an empty TransferData object; this object will be filled in on return with the platform specific representation of the data- Throws:
SWTException
-- ERROR_INVALID_DATA - if object does not contain data in a valid format or is
null
- ERROR_INVALID_DATA - if object does not contain data in a valid format or is
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nativeToJava
Converts a platform specific representation of data to a java representation.- Parameters:
transferData
- the platform specific representation of the data to be converted- Returns:
- a java representation of the converted data if the conversion was
successful; otherwise null. If transferData is
null
thennull
is returned. The type of Object that is returned is dependent on theTransfer
subclass.
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registerType
Registers a name for a data type and returns the associated unique identifier.You may register the same type more than once, the same unique identifier will be returned if the type has been previously registered.
Note: On windows, do not call this method with pre-defined Clipboard Format types such as CF_TEXT or CF_BITMAP because the pre-defined identifier will not be returned
- Parameters:
formatName
- the name of a data type- Returns:
- the unique identifier associated with this data type
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validate
Test that the object is of the correct format for this Transfer class.- Parameters:
object
- a java representation of the data to be converted- Returns:
- true if object is of the correct form for this transfer type
- Since:
- 3.1
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