JavaFx中Controller獲取Stage並自定義視窗移動與縮放邏輯

摘要： JavaFx中Controller獲取Stage並自定義視窗移動與縮放邏輯 由於去掉了平臺自帶了標題欄，視窗就無法移動和縮放了，需要我們自己來實現。 去除視窗標題欄 public class Main extends Application { @Override ...

JavaFx中Controller獲取Stage並自定義視窗移動與縮放邏輯

由於去掉了平臺自帶了標題欄，視窗就無法移動和縮放了，需要我們自己來實現。

去除視窗標題欄

public class Main extends Application {

@Override
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("main.fxml"));
primaryStage.setTitle("main");
// 主要是這一句
primaryStage.initStyle(StageStyle.TRANSPARENT);
primaryStage.setScene(new Scene(root));
primaryStage.show();
}


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

在Controller中獲取Stage

首先確定在Controller中獲取到你的跟佈局物件，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">
<!--其他佈局元素-->
</BorderPane>

然後可以在public void initialize(URL url, ResourceBundle resourceBundle) 方法內獲取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;
}

}

自定義窗體移動與縮放邏輯

1. 記錄滑鼠座標

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

2. 自定義移動控制區域

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

3. 判斷滑鼠座標位置，並處理游標變換

   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. 處理視窗縮放

   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);
   }

完整程式碼

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);
}
}