com.alee.managers.drag.view.NodesDragViewHandler Maven / Gradle / Ivy
/*
* This file is part of WebLookAndFeel library.
*
* WebLookAndFeel library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* WebLookAndFeel library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with WebLookAndFeel library. If not, see {@link MutableTreeNode} type
* @author Mikle Garin
* @see How to use DragManager
* @see com.alee.managers.drag.DragManager
*/
public abstract class NodesDragViewHandler implements DragViewHandler>
{
/**
* Returns maximum amount of {@link MutableTreeNode}s displayed when dragged.
* If there are more {@link MutableTreeNode}s than limit allows additional label will be added informing about it.
*
* @return maximum amount of {@link MutableTreeNode}s displayed when dragged
*/
public abstract int getNodesViewLimit ();
/**
* Retturns additional X offset for "more" text.
* Might be useful to move this text according to {@link MutableTreeNode} icons.
*
* @return additional X offset for "more" text
*/
public Insets getMoreTextMargin ()
{
return new Insets ( 0, 0, 0, 0 );
}
@NotNull
@Override
public BufferedImage getView ( @NotNull final List nodes, @NotNull final DragSourceDragEvent dragSourceDragEvent )
{
BufferedImage view = null;
if ( dragSourceDragEvent.getSource () instanceof DragSourceContext )
{
final DragSourceContext dsc = ( DragSourceContext ) dragSourceDragEvent.getSource ();
if ( dsc.getComponent () instanceof WebTree )
{
final WebTree tree = ( WebTree ) dsc.getComponent ();
final TreeModel model = tree.getModel ();
if ( model != null )
{
final List realNodes;
if ( nodes.get ( 0 ) instanceof UniqueNode )
{
final List uniqueNodes = ( List ) nodes;
if ( tree instanceof WebExTree )
{
final WebExTree exTree = ( WebExTree ) tree;
realNodes = new ArrayList ();
for ( final UniqueNode node : uniqueNodes )
{
realNodes.add ( ( N ) exTree.findNode ( node.getId () ) );
}
}
else if ( tree instanceof WebAsyncTree )
{
final WebAsyncTree exTree = ( WebAsyncTree ) tree;
realNodes = new ArrayList ();
for ( final UniqueNode node : uniqueNodes )
{
realNodes.add ( ( N ) exTree.findNode ( node.getId () ) );
}
}
else
{
realNodes = nodes;
}
}
else
{
realNodes = nodes;
}
final FontMetrics fm = tree.getFontMetrics ( tree.getFont () );
final int fmh = fm.getHeight ();
final int limit = getNodesViewLimit ();
final int amount = realNodes.size () - limit;
final String text = amount > 1 ? "And %s more elements" : "And one more element";
final String moreText = limit > 0 ? String.format ( text, amount ) : null;
final Insets moreTextOffset = getMoreTextMargin ();
int width = 0;
int height = 0;
int count = 0;
for ( final N node : realNodes )
{
if ( limit <= 0 || limit > count )
{
// todo This can potentially cause inconsistent preview size
final Rectangle bounds = tree.getNodeBounds ( node );
if ( bounds != null )
{
width = Math.max ( bounds.width, width );
height += bounds.height;
count++;
}
}
else
{
width = Math.max ( moreTextOffset.left + fm.stringWidth ( moreText ) + moreTextOffset.right, width );
height += moreTextOffset.top + fmh + moreTextOffset.bottom;
break;
}
}
final BufferedImage image = ImageUtils.createCompatibleImage ( width, height, BufferedImage.TRANSLUCENT );
final Graphics2D g2d = image.createGraphics ();
int y = 0;
count = 0;
final TreeCellRenderer cellRenderer = tree.getCellRenderer ();
final CellRendererPane rendererPane = tree.getUI ().getCellRendererPane ();
for ( final N node : realNodes )
{
if ( limit <= 0 || limit > count )
{
final Component renderer = cellRenderer.getTreeCellRendererComponent (
tree,
node,
false,
tree.isExpanded ( node ),
model.isLeaf ( node ),
tree.getRowForNode ( node ),
false
);
final Dimension ps = renderer.getPreferredSize ();
rendererPane.paintComponent ( g2d, renderer, null, 0, y, ps.width, ps.height );
y += ps.height;
count++;
}
else
{
SwingUtils.setupTextAntialias ( g2d );
g2d.setPaint ( Color.BLACK );
g2d.drawString ( moreText, moreTextOffset.left,
y + moreTextOffset.top + fmh / 2 + LafUtils.getTextCenterShiftY ( fm ) );
break;
}
}
g2d.dispose ();
view = image;
}
}
}
if ( view == null )
{
throw new DragException ( "Unable to create nodes drag view: " + TextUtils.listToString ( nodes ) );
}
return view;
}
@NotNull
@Override
public Point getViewRelativeLocation ( @NotNull final List nodes, final DragSourceDragEvent dragSourceDragEvent,
@NotNull final BufferedImage view )
{
return new Point ( 25, 5 );
}
@Override
public void dragEnded ( @NotNull final List nodes, @NotNull final DragSourceDropEvent event )
{
/**
* Don't need to do anything on drag end.
*/
}
} © 2015 - 2025 Weber Informatics LLC | Privacy Policy