Allow user to resize an undecorated Stage
I am working on making a screen recorder in JavaFX and one utility that is mandatory in the screen recorder is to let the user define how much area to record.
I managed to make an undecorated , semi-transparent Stage that can be dragged around to define the area and added a close button to let the user confirm the area which is to be recorded.
Now, how do I let the user resize the stage by dragging it by its edges ?
SSCCE:
package draggable;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.geometry.Rectangle2D;
import javafx.scene.Scene;
import javafx.scene.SceneBuilder;
import javafx.scene.control.Button;
import javafx.scene.control.ButtonBuilder;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.StackPaneBuilder;
import javafx.scene.paint.Color;
import javafx.stage.Screen;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
public class DraggableStage extends Application{
Button close;
StackPane holder;
Rectangle2D maxBounds;
Scene theScene;
double pressedX;
double pressedY;
double draggedX;
double draggedY;
@Override
public void start(Stage stage) throws Exception {
final Stage theStage = stage;
// determine how big the screen is
maxBounds = Screen.getPrimary().getVisualBounds();
//create the close button
close = ButtonBuilder
.create()
.text("Close")
.build();
//create the StackPane holder for the button
holder = StackPaneBuilder
.create()
.alignment(Pos.CENTER)
.children(close)
.build();
// you cannot resize the screen beyond the max resolution of the screen
holder.setMaxSize(maxBounds.getWidth(), maxBounds.getHeight());
//you cannot resize under half the width and height of the screen
holder.setMinSize(maxBounds.getWidth() / 2,maxBounds.getHeight() / 2);
//the scene where it all happens
theScene = SceneBuilder
.create()
.root(holder)
.width(maxBounds.getWidth() / 2)
.height(maxBounds.getHeight() / 2)
.build();
// add the button listeners
close.setOnAction(new EventHandler<ActionEvent>(){
@Override
public void handle(ActionEvent event) {
theStage.close();
}
});
// add the drag and press listener for the StackPane
holder.setOnMousePressed(new EventHandler<MouseEvent>(){
@Override
public void handle(MouseEvent e) {
pressedX = e.getX();
pressedY = e.getY();
}
});
holder.setOnMouseDragged(new EventHandler<MouseEvent>(){
@Override
public void handle(MouseEvent e) {
draggedX = e.getX();
draggedY = e.getY();
double differenceX = draggedX - pressedX;
double differenceY = draggedY - pressedY;
theStage.setX(theStage.getX() + differenceX);
theStage.setY(theStage.getY() + differenceY);
}
});
//the mandatory mumbo jumbo
theScene.setFill(Color.rgb(128, 128, 128, 0.5));
stage.initStyle(StageStyle.TRANSPARENT);
stage.setScene(theScene);
stage.sizeToScene();
stage.show();
}
public static void main(String[] args) {
Application.launch("draggable.DraggableStage");
}
}
Image:
Answer
I created a ResizeHelper class which can help you in that case, usage:
ResizeHelper.addResizeListener(yourStage);
the helper class:
import javafx.collections.ObservableList;
import javafx.event.EventHandler;
import javafx.event.EventType;
import javafx.scene.Cursor;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.stage.Stage;
//created by Alexander Berg
public class ResizeHelper {
public static void addResizeListener(Stage stage) {
ResizeListener resizeListener = new ResizeListener(stage);
stage.getScene().addEventHandler(MouseEvent.MOUSE_MOVED, resizeListener);
stage.getScene().addEventHandler(MouseEvent.MOUSE_PRESSED, resizeListener);
stage.getScene().addEventHandler(MouseEvent.MOUSE_DRAGGED, resizeListener);
stage.getScene().addEventHandler(MouseEvent.MOUSE_EXITED, resizeListener);
stage.getScene().addEventHandler(MouseEvent.MOUSE_EXITED_TARGET, resizeListener);
ObservableList<Node> children = stage.getScene().getRoot().getChildrenUnmodifiable();
for (Node child : children) {
addListenerDeeply(child, resizeListener);
}
}
public static void addListenerDeeply(Node node, EventHandler<MouseEvent> listener) {
node.addEventHandler(MouseEvent.MOUSE_MOVED, listener);
node.addEventHandler(MouseEvent.MOUSE_PRESSED, listener);
node.addEventHandler(MouseEvent.MOUSE_DRAGGED, listener);
node.addEventHandler(MouseEvent.MOUSE_EXITED, listener);
node.addEventHandler(MouseEvent.MOUSE_EXITED_TARGET, listener);
if (node instanceof Parent) {
Parent parent = (Parent) node;
ObservableList<Node> children = parent.getChildrenUnmodifiable();
for (Node child : children) {
addListenerDeeply(child, listener);
}
}
}
static class ResizeListener implements EventHandler<MouseEvent> {
private Stage stage;
private Cursor cursorEvent = Cursor.DEFAULT;
private int border = 4;
private double startX = 0;
private double startY = 0;
public ResizeListener(Stage stage) {
this.stage = stage;
}
@Override
public void handle(MouseEvent mouseEvent) {
EventType<? extends MouseEvent> mouseEventType = mouseEvent.getEventType();
Scene scene = stage.getScene();
double mouseEventX = mouseEvent.getSceneX(),
mouseEventY = mouseEvent.getSceneY(),
sceneWidth = scene.getWidth(),
sceneHeight = scene.getHeight();
if (MouseEvent.MOUSE_MOVED.equals(mouseEventType) == true) {
if (mouseEventX < border && mouseEventY < border) {
cursorEvent = Cursor.NW_RESIZE;
} else if (mouseEventX < border && mouseEventY > sceneHeight - border) {
cursorEvent = Cursor.SW_RESIZE;
} else if (mouseEventX > sceneWidth - border && mouseEventY < border) {
cursorEvent = Cursor.NE_RESIZE;
} else if (mouseEventX > sceneWidth - border && mouseEventY > sceneHeight - border) {
cursorEvent = Cursor.SE_RESIZE;
} else if (mouseEventX < border) {
cursorEvent = Cursor.W_RESIZE;
} else if (mouseEventX > sceneWidth - border) {
cursorEvent = Cursor.E_RESIZE;
} else if (mouseEventY < border) {
cursorEvent = Cursor.N_RESIZE;
} else if (mouseEventY > sceneHeight - border) {
cursorEvent = Cursor.S_RESIZE;
} else {
cursorEvent = Cursor.DEFAULT;
}
scene.setCursor(cursorEvent);
} else if(MouseEvent.MOUSE_EXITED.equals(mouseEventType) || MouseEvent.MOUSE_EXITED_TARGET.equals(mouseEventType)){
scene.setCursor(Cursor.DEFAULT);
} else if (MouseEvent.MOUSE_PRESSED.equals(mouseEventType) == true) {
startX = stage.getWidth() - mouseEventX;
startY = stage.getHeight() - mouseEventY;
} else if (MouseEvent.MOUSE_DRAGGED.equals(mouseEventType) == true) {
if (Cursor.DEFAULT.equals(cursorEvent) == false) {
if (Cursor.W_RESIZE.equals(cursorEvent) == false && Cursor.E_RESIZE.equals(cursorEvent) == false) {
double minHeight = stage.getMinHeight() > (border*2) ? stage.getMinHeight() : (border*2);
if (Cursor.NW_RESIZE.equals(cursorEvent) == true || Cursor.N_RESIZE.equals(cursorEvent) == true || Cursor.NE_RESIZE.equals(cursorEvent) == true) {
if (stage.getHeight() > minHeight || mouseEventY < 0) {
stage.setHeight(stage.getY() - mouseEvent.getScreenY() + stage.getHeight());
stage.setY(mouseEvent.getScreenY());
}
} else {
if (stage.getHeight() > minHeight || mouseEventY + startY - stage.getHeight() > 0) {
stage.setHeight(mouseEventY + startY);
}
}
}
if (Cursor.N_RESIZE.equals(cursorEvent) == false && Cursor.S_RESIZE.equals(cursorEvent) == false) {
double minWidth = stage.getMinWidth() > (border*2) ? stage.getMinWidth() : (border*2);
if (Cursor.NW_RESIZE.equals(cursorEvent) == true || Cursor.W_RESIZE.equals(cursorEvent) == true || Cursor.SW_RESIZE.equals(cursorEvent) == true) {
if (stage.getWidth() > minWidth || mouseEventX < 0) {
stage.setWidth(stage.getX() - mouseEvent.getScreenX() + stage.getWidth());
stage.setX(mouseEvent.getScreenX());
}
} else {
if (stage.getWidth() > minWidth || mouseEventX + startX - stage.getWidth() > 0) {
stage.setWidth(mouseEventX + startX);
}
}
}
}
}
}
}
}