bibliothek.gui.dock.station.layer
Interface DockStationDropLayer

All Known Implementing Classes:

DefaultDropLayer, FlapOverrideDropLayer, FlapSideDropLayer, ScreenLayer, ScreenWindowLayer, SideSnapDropLayer, SplitOverrideDropLayer, TabDropLayer, WindowDropLayer

public interface DockStationDropLayer

A DockStationDropLayer describes an area of the screen where a drag and drop operation can end with the "drop event". Several levels can be active at the same time, and there is a strong order in which level is more important than the other level, the first level hit by the mouse wins.
The order of two DockStationDropLayers is calculated by applying the following steps, the first conclusive result is the final result.

• If either of the levels return true on canCompare(DockStationDropLayer), then the compare(DockStationDropLayer) method is called for comparison. If both levels implement the compare method but the results contradict each other, then this step is ignored.
• The LayerPrioritys are compared, the one level where LayerPriority.getPriority() is higher also has a higher priority.
• If the result of LayerPriority.isReverse() does not match, the level where reverse is false has higher priority.
• Depending on the result of LayerPriority.isReverse() the result of the remaining steps is inverted.
• If the station of one level is an ancestor of the other level, then the child station has higher priority.
• Otherwise one level randomly has a higher priority than the other.

Levels whose contains(int, int) method returns false for the current position of the mouse are ignored for the order, but not when calling modify.

Author:

Benjamin Sigg

Method Summary

boolean	canCompare(DockStationDropLayer level) Tells whether this level contains code to tell whether it has a higher or lower priority as level.
int	compare(DockStationDropLayer level) Compares this level with level.
boolean	contains(int x, int y) Tells whether this level contains the point x/y, which is the position of the mouse on the screen.
Component	getComponent() Gets a Component which is associated with this level.
LayerPriority	getPriority() Gets the basic priority of this level.
DockStation	getStation() Gets the DockStation which created this level.
DockStationDropLayer	modify(DockStationDropLayer child) This method is called for any DockStationDropLayer whose station is a child to the station of this level.
void	setPriority(LayerPriority priority) Sets a new priority for this level.

Method Detail

getStation

DockStation getStation()

Gets the DockStation which created this level.

Returns:

the creator and owner of this level

getComponent

Component getComponent()

Gets a Component which is associated with this level. The Component can be used to order levels because Components can overlap each other. This is an optional method, a result of null is perfectly valid.

Returns:

some component or null

modify

DockStationDropLayer modify(DockStationDropLayer child)

This method is called for any DockStationDropLayer whose station is a child to the station of this level. This method may modify the level, e.g. increase or decrease its priority. This method is called before this level itself gets modified by its parents. This method is called independent of whether contains(int, int) returns true or false.

Parameters:

child - the child to modify, this method may either directly modify child, create a wrapper or a copy of child

Returns:

either child or a new DockStationDropLayer replacing child, not null

contains

boolean contains(int x,
                 int y)

Tells whether this level contains the point x/y, which is the position of the mouse on the screen.

Parameters:

x - the x-coordinate of the mouse on the screen

y - the y-coordinate of the mouse on the screen

Returns:

true if this level contains x/y, false otherwise

getPriority

LayerPriority getPriority()

Gets the basic priority of this level.

Returns:

the basic priority, must not be null

setPriority

void setPriority(LayerPriority priority)

Sets a new priority for this level.

Parameters:

priority - the new priority, must not be null

canCompare

boolean canCompare(DockStationDropLayer level)

Tells whether this level contains code to tell whether it has a higher or lower priority as level. For most implementations the result of this method should be false.
If this method returns true, then the ordering defined by the custom algorithm supercedes any other conditions.

Parameters:

level - some other level to check

Returns:

true if this DockStationDropLayer contains code to compare level with this

compare

int compare(DockStationDropLayer level)

Compares this level with level. This method is only called if canCompare(DockStationDropLayer) returned true for level. This method works like Comparable.compareTo(Object).

Parameters:

level - another level to compare

Returns:

a number less/equal/higher than zero, if this level has higher/equal/lesser priority than level.