JavaFx中Controller获取Stage并自定义窗口移动与缩放逻辑

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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

记录鼠标坐标
root.setOnMousePressed(event -> {
event.consume();
xOffset = event.getSceneX();
yOffset = event.getSceneY();
});

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);
});

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);
}

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);
}
}