Get currently displaying tooltip

问题

Is there some way to copy the currently displayed tooltip to the clipboard as a string without complex XY-coord calculation that maps to the tooltip text area? This is especially challenging on a chart with tooltip displayed at an angle, also to only capture if being displayed. For example to get ctl-c to copy the displaying tooltip to clipboard:

PlotThisDaysData extends JFrame implements ... KeyListener{

@Override
public void keyTyped( KeyEvent e ) {
    char typed = e.getKeyChar();
    if ( typed == KeyEvent.VK_C ) /*VK_C?*/ {

        String tooltipStr = myChart.???();  // <<<<<<<<<<<<< get displaying tooltip <<<<

        StringSelection selection = new StringSelection( tooltipStr );
        Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
        clipboard.setContents( selection, selection );
    }
}

Perhaps there is some event when a tooltip gets displayed so I can store a String pointer and use when ctl-c is entered?

回答1:

Tooltips are displayed in response to mouse events received by the chart's enclosing ChartPanel. To copy the currently displayed tooltip to the clipboard as the mouse moves,

1. Add a ChartMouseListener to the chart panel, as shown here.

2. When your listener sees a desired ChartEntity, ask the ChartPanel for the relevant text and copy it to the clipboard.

   Toolkit toolkit = Toolkit.getDefaultToolkit();
   Clipboard clipboard = toolkit.getSystemClipboard();
   …
       @Override
       public void chartMouseMoved(ChartMouseEvent cme) {
           …
           String t = chartPanel.getToolTipText(cme.getTrigger());
           clipboard.setContents(new StringSelection(t), null);
       }
   

A similar approach can be used in a key binding, as shown here. Use the chart panel's getMousePosition() to construct the required MouseEvent trigger.

1. Get the chart panel's InputMap, ActionMap, and the platform's shortcut mask.

   InputMap im = chartPanel.getInputMap();
   ActionMap am = chartPanel.getActionMap();
   int mask = Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
   

2. Put the desired KeyStroke in the chart panel's InputMap

   im.put(KeyStroke.getKeyStroke(KeyEvent.VK_C, mask), "copytip");
   

3. Put the corresponding Action in the chart panel's ActionMap

   am.put("copytip", new AbstractAction() {
       @Override
       public void actionPerformed(ActionEvent e) {
           Point p = chartPanel.getMousePosition();
           String t = chartPanel.getToolTipText(new MouseEvent(chartPanel,
               0, System.currentTimeMillis(), 0, p.x, p.y, 0, false));
           clipboard.setContents(new StringSelection(t), null);
       }
   });
   

Avoid KeyListener, as it requires keyboard focus.

来源：https://stackoverflow.com/questions/45762805/get-currently-displaying-tooltip