JavaFx中Controller获取Stage并自定义窗口移动与缩放逻辑

JavaFx中Controller获取Stage并自定义窗口移动与缩放逻辑

由于去掉了平台自带了标题栏，窗口就无法移动和缩放了，需要我们自己来实现。

去除窗口标题栏

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("main.fxml"));
        primaryStage.setTitle("main");
        // 主要是这一句
        primaryStage.initStyle(StageStyle.TRANSPARENT);
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }


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

在Controller中获取Stage

首先确定在Controller中获取到你的跟布局对象，如下：

public class Controller implements Initializable {
    public BorderPane root;
    private Stage stage;
}

<BorderPane fx:id="root" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" stylesheets="@../css/main.css" xmlns="http://javafx.com/javafx/8.0.172-ea" xmlns:fx="http://javafx.com/fxml/1" fx:controller="line.main.Controller">
      <!--其他布局元素-->
</BorderPane>

然后可以在 public void initialize(URL url, ResourceBundle resourceBundle) 方法内获取Stage

public class Controller implements Initializable {
    public BorderPane root;
    private Stage stage;

    @Override
    public void initialize(URL url, ResourceBundle resourceBundle) {
       var stage = getStage();
    }

    private Stage getStage() {
        if (stage == null) {
            stage = (Stage) root.getScene().getWindow();
        }
        return stage;
    }

}

自定义窗体移动与缩放逻辑

1. 记录鼠标坐标

   root.setOnMousePressed(event -> {
               event.consume();
               xOffset = event.getSceneX();
               yOffset = event.getSceneY();
           });

2. 自定义移动控制区域

   dragArea.setOnMouseDragged(event -> {
               event.consume();
               var stage = getStage();
               stage.setX(event.getScreenX() - xOffset);
               stage.setY(event.getScreenY() - yOffset);
           });

3. 判断鼠标坐标位置，并处理光标变换

   root.setOnMouseMoved(this::mouseMoveHandle);
   
    private void mouseMoveHandle(MouseEvent event) {
           event.consume();
           double x = event.getSceneX();
           double y = event.getSceneY();
           var stage = getStage();
           double width = stage.getWidth();
           double height = stage.getHeight();
           Cursor cursorType = Cursor.DEFAULT;
           bit = 0;
           if (y >= height - RESIZE_WIDTH) {
               if (x <= RESIZE_WIDTH) {
                   bit |= 1 << 3;
               } else if (x >= width - RESIZE_WIDTH) {
                   bit |= 1;
                   bit |= 1 << 2;
                   cursorType = Cursor.SE_RESIZE;
               } else {
                   bit |= 1;
                   cursorType = Cursor.S_RESIZE;
               }
           } else if (x >= width - RESIZE_WIDTH) {
               bit |= 1 << 2;
               cursorType = Cursor.E_RESIZE;
           }
           root.setCursor(cursorType);
       }

4. 处理窗口缩放

   root.setOnMouseDragged(this::mouseDraggedHandle);
   
   private void mouseDraggedHandle(MouseEvent event) {
       event.consume();
       var primaryStage = getStage();
       double x = event.getSceneX();
       double y = event.getSceneY();
       double nextX = primaryStage.getX();
       double nextY = primaryStage.getY();
       double nextWidth = primaryStage.getWidth();
       double nextHeight = primaryStage.getHeight();
       if ((bit & 1 << 2) != 0) {
           nextWidth = x;
       }
       if ((bit & 1) != 0) {
           nextHeight = y;
       }
       if (nextWidth <= MIN_WIDTH) {
           nextWidth = MIN_WIDTH;
       }
       if (nextHeight <= MIN_HEIGHT) {
           nextHeight = MIN_HEIGHT;
       }
       primaryStage.setX(nextX);
       primaryStage.setY(nextY);
       primaryStage.setWidth(nextWidth);
       primaryStage.setHeight(nextHeight);
   }

完整代码

package line.main;

import javafx.fxml.Initializable;
import javafx.scene.Cursor;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

import java.net.URL;
import java.util.ResourceBundle;

public class Controller implements Initializable {
    public BorderPane root;
    public Pane dragArea;
    private Stage stage;
    private double xOffset = 0;
    private double yOffset = 0;
    private int bit = 0;//left,right,top,bottom
    private static final double RESIZE_WIDTH = 5.00;
    private static final double MIN_WIDTH = 600.00;
    private static final double MIN_HEIGHT = 400.00;

    @Override
    public void initialize(URL url, ResourceBundle resourceBundle) {
        dragArea.setOnMouseDragged(event -> {
            event.consume();
            var stage = getStage();
            stage.setX(event.getScreenX() - xOffset);
            stage.setY(event.getScreenY() - yOffset);
        });
        root.setOnMousePressed(event -> {
            event.consume();
            xOffset = event.getSceneX();
            yOffset = event.getSceneY();
        });
        root.setOnMouseMoved(this::mouseMoveHandle);
        root.setOnMouseDragged(this::mouseDraggedHandle);
    }

    private Stage getStage() {
        if (stage == null) {
            stage = (Stage) root.getScene().getWindow();
        }
        return stage;
    }

    private void mouseMoveHandle(MouseEvent event) {
        event.consume();
        double x = event.getSceneX();
        double y = event.getSceneY();
        var stage = getStage();
        double width = stage.getWidth();
        double height = stage.getHeight();
        Cursor cursorType = Cursor.DEFAULT;
        bit = 0;
        if (y >= height - RESIZE_WIDTH) {
            if (x <= RESIZE_WIDTH) {
                bit |= 1 << 3;
            } else if (x >= width - RESIZE_WIDTH) {
                bit |= 1;
                bit |= 1 << 2;
                cursorType = Cursor.SE_RESIZE;
            } else {
                bit |= 1;
                cursorType = Cursor.S_RESIZE;
            }
        } else if (x >= width - RESIZE_WIDTH) {
            bit |= 1 << 2;
            cursorType = Cursor.E_RESIZE;
        }
        root.setCursor(cursorType);
    }

    private void mouseDraggedHandle(MouseEvent event) {
        event.consume();
        var primaryStage = getStage();
        double x = event.getSceneX();
        double y = event.getSceneY();
        double nextX = primaryStage.getX();
        double nextY = primaryStage.getY();
        double nextWidth = primaryStage.getWidth();
        double nextHeight = primaryStage.getHeight();
        if ((bit & 1 << 2) != 0) {
            nextWidth = x;
        }
        if ((bit & 1) != 0) {
            nextHeight = y;
        }
        if (nextWidth <= MIN_WIDTH) {
            nextWidth = MIN_WIDTH;
        }
        if (nextHeight <= MIN_HEIGHT) {
            nextHeight = MIN_HEIGHT;
        }
        primaryStage.setX(nextX);
        primaryStage.setY(nextY);
        primaryStage.setWidth(nextWidth);
        primaryStage.setHeight(nextHeight);
    }
}