JavaFX节点的Focus Listener [英] Focus Listener for JavaFX Nodes

问题描述

我是JavaFX的初学者。我真的陷入了困境。 :(抱歉，如果我的英语很差。

我的JavaFX程序中有两个堆栈窗格。我想在这两个堆栈窗格中添加一个焦点监听器。 / p>

当我点击一个堆栈窗格时，它应该激活此堆栈窗格的焦点获取方法。

一旦我点击另一个堆栈窗格，第一个堆栈窗格应该调用它的焦点丢失方法，并且应该调用当前堆栈窗格的focus gain方法。就像我们在Swing包中有焦点事件一样。

目前我试过这个：

  stackPane.focusedProperty（） .addListener（new ChangeListener< Boolean>（）{
 
 @Override 
 public void changed（ObservableValue<？extends Boolean> observable，Boolean oldValue，Boolean newValue）{
 if（
 if（ newValue.booleanValue（））{
 focusGained（stackPane）; 
} else {
 focusLost（stackPane）; 
} 
} 
}）; 
 
 private void focusGained（StackPane stackPane）{
 System.out.println（Focus Gained。）; 
} 
 
 private void focusLost（StackPane stackPane）{
 System.out.println（Focus Lost。）; 
} 
  

我还尝试在堆栈窗格上设置焦点遍历属性，即

  stackPane.setFocusTraversable（true）; 
  

这些都无法正常工作。当我运行它时，输出只显示这3行，无论我点击堆栈窗格多少次。

 焦点获得。 
专注迷失。 
焦点获得。 
  

请帮助。

解决方案

嗯，这有点晚了，但可能有助于其他人。
这很好用：

  root.focusedProperty（）。addListener（（ObservableValue<？extends Boolean> observable，Boolean oldValue，Boolean newValue） - > {
 focusState（newValue）; 
}）; 
 
 private void focusState（boolean value）{
 if（value）{
 System.out.println（Focus Gained）; 
} 
 else {
 System.out.println（Focus Lost）; 
} 
} 
  

I am a beginner in JavaFX. I am really stuck at this point. :( And sorry if my English is poor.

I have two stack panes in my JavaFX program. I want to add a focus listener to both of these stack panes.

It should be such that, when I click on one stack pane, it should activate the focus gained method for this stack pane.

Once I click on another stack pane, the 1st stack pane should give a call to its focus lost method, and the current stack pane's focus gained method should be called. Just like we have focus events in the Swing Package.

Currently I have tried this:

stackPane.focusedProperty().addListener(new ChangeListener<Boolean>() {

                @Override
                public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
                    if (newValue.booleanValue()) {
                        focusGained(stackPane);
                    } else {
                        focusLost(stackPane);
                    }
                }
            });

private void focusGained(StackPane stackPane){
    System.out.println("Focus Gained.");
}

private void focusLost(StackPane stackPane){
    System.out.println("Focus Lost.");
}

I have also tried to set the focus traversable property on the stack pane i.e.

stackPane.setFocusTraversable(true);

These are not working properly. When I run it, the output only shows these 3 lines, no matter how many times I click on the stack panes.

Focus Gained.
Focus Lost.
Focus Gained.

Please help.

解决方案

Well, it's a bit late but it might help others. This works fine:

root.focusedProperty().addListener((ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) -> {
    focusState(newValue);
});

private void focusState(boolean value) {
    if (value) {
        System.out.println("Focus Gained");
    }
    else {
        System.out.println("Focus Lost");
    }
}

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