提问
我在JPanel中显示了一个钟形树.我的树的构造函数如下所示: Forest<String, Integer> graph = new DelegateForest<String, Integer>();
static GraphZoomScrollPane panel = null;
static DefaultModalGraphMouse graphMouse = null;
static JComboBox modeBox = null;
static ScalingControl scaler;
public PanelTree(List<Cluster> clist) {
setBounds(215, 10, 550, 550);
updateData(clist); // adds vertex and edges to graph
treeLayout = new TreeLayout<String, Integer>(graph);
vv = new VisualizationViewer<String, Integer>(treeLayout, new Dimension(500, 500));
vv.setBackground(Color.white);
vv.getRenderContext().setEdgeShapeTransformer(new EdgeShape.Line());
vv.getRenderContext().setVertexLabelTransformer(new ToStringLabeller());
// add a listener for ToolTips
vv.setVertexToolTipTransformer(new ToStringLabeller());
vv.getRenderContext()
.setArrowFillPaintTransformer(new ConstantTransformer(Color.lightGray));
panel = new GraphZoomScrollPane(vv);
add(panel);
graphMouse = new DefaultModalGraphMouse();
vv.setGraphMouse(graphMouse);
modeBox = graphMouse.getModeComboBox();
modeBox.addItemListener(graphMouse.getModeListener());
graphMouse.setMode(ModalGraphMouse.Mode.TRANSFORMING);
scaler = new CrossoverScalingControl();
}
但是树很大.因此,我想知道是否有一种方法可以自动缩小以使树适合窗口,否则可以设置一个默认缩放,该默认缩放小于默认缩放.我怎样才能做到这一点 ?
最佳答案
ScalingControl scaler = new CrossoverScalingControl();
public void zoomIn() {
setZoom(1);
}
public void zoomOut() {
setZoom(-1);
}
private void setZoom(int amount) {
scaler.scale(vv, amount > 0 ? 1.1f : 1 / 1.1f, vv.getCenter());
}
要使图形适合窗口,您可以计算图形大小和面板大小之间的差异,然后调用setZoom()方法并传递差异因子.