在Java FX中，如何从左上角（而不是左下角）开始绘制文本？

Question

使用Java FX，文本x和y坐标指的是文本的左下角。如何使坐标参考左上角？例如，如果在原点（0,0）处绘制了文本，则该文本将退出屏幕，但在这种情况下，我们希望将其显示在左上方。

public class JavaFxOriginText extends Application  {

    public static void main(String[] args) {
        Application.launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        Group root = new Group();
        Scene scene = new Scene(root, 100, 50, Color.WHITE);
        primaryStage.setScene(scene);
        primaryStage.show();

        for(int i=0; i<5; i++) {
            Text text = new Text(0, i*10, "Hello World! " + i);
            text.setFill(Color.BLACK);
            root.getChildren().add(text);
        }
    }
}

此代码段显示

但是显示中缺少“ Hello World！0”。

Answer 1

Set the text origin to VPos.TOP (default is VPos.BASELINE):

Text text = new text(15, 0, "The Thirty-Nine Steps");
text.setTextOrigin(VPos.TOP);

Defines the origin of text coordinate system in local coordinates.

You might also wish to set the text bounds type to TextBoundsType.VISUAL (default is TextBoundsType.LOGICAL):

text.setBoundsType(TextBoundsType.VISUAL);

The geometry of text can be measured either in terms of the bounds of the particular text to be rendered - visual bounds, or as properties of the font and the characters to be rendered - logical bounds. Visual bounds are more useful for positioning text as graphics, and for obtaining tight enclosing bounds around the text.