ITI0011:praktikum 9 T8
Tagasi ITI0011 lehele.
Üldine
Praktikum: 28.10.2014 kell 8:00
Teemad:
- JavaFX
- JavaFX klassi arvutites
- Layout, Pane
- Shapes
- mouse event
Koodinäite
<source lang="java">
import javafx.application.Application; import javafx.event.EventHandler; import javafx.scene.Node; import javafx.scene.Scene; import javafx.scene.control.Menu; import javafx.scene.control.MenuBar; import javafx.scene.control.MenuItem; import javafx.scene.input.MouseButton; import javafx.scene.input.MouseEvent; import javafx.scene.layout.BorderPane; import javafx.scene.layout.Pane; import javafx.scene.shape.Polyline; import javafx.scene.shape.Rectangle; import javafx.stage.Stage;
public class Main extends Application {
class MyHandler implements EventHandler<MouseEvent> {
@Override public void handle(MouseEvent event) {
}
}
public static void main(String[] args) { launch(args); }
private double oldX = 0, oldY = 0; @Override public void start(Stage primaryStage) throws Exception { BorderPane root = new BorderPane();
Scene scene = new Scene(root, 500, 500);
primaryStage.setScene(scene); primaryStage.show();
MenuBar menuBar = new MenuBar(); Menu menuFile = new Menu("File"); MenuItem menuFileSave = new MenuItem("Save"); menuBar.getMenus().add(menuFile); menuFile.getItems().add(menuFileSave);
root.setTop(menuBar);
Pane main = new Pane(); root.setCenter(main);
Rectangle r1 = new Rectangle(10, 10, 100, 100); Rectangle r2 = new Rectangle(100, 100, 50, 20); main.getChildren().add(r1); main.getChildren().add(r2);
//EventHandler<MouseEvent> mouseHandler = new MyHandler();
EventHandler<MouseEvent> mouseHandler = new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent event) { if (event.getEventType() == MouseEvent.MOUSE_PRESSED) { if (event.getButton() == MouseButton.SECONDARY) { Polyline line = new Polyline(); line.getPoints().add(event.getX()); line.getPoints().add(event.getY()); main.getChildren().add(line); } oldX = event.getX(); } else { // drag if (event.getButton() == MouseButton.PRIMARY) { for (Node s : main.getChildren()) { if (s instanceof Rectangle) { Rectangle r = (Rectangle)s; r.setX(r.getX() + (event.getX() - oldX)); } } } else { //secondary for (Node s : main.getChildren()) { if (s instanceof Polyline) { Polyline p = (Polyline)s; if (p.getPoints().size() < 4) { p.getPoints().add(event.getX()); p.getPoints().add(event.getY()); } else { p.getPoints().set(2, event.getX()); p.getPoints().set(3, event.getY()); } } } } } oldX = event.getX();
} };
main.setOnMousePressed(mouseHandler); main.setOnMouseDragged(mouseHandler); }
}
</source>
Exercise
Create an application which allows the user to draw a rectangle. There are several options how to achieve this:
- using mouse dragging: the starting point is fixed when the dragging starts (mouse press), the opposite corner moves along while dragging. if the dragging ends, the rectangle is fixed.
- using clicking: when clicking first time, one point is fixed, when clicking another time, the opposite corner is fixed (and rectangle is drawn).
- some other way
Optional requirements:
- more than one rectangle can be drawn