在 JavaFX 中将元素动态添加到固定大小的 GridPane

Dynamically add elements to a fixed-size GridPane in JavaFX

提问by Koln

I would like to display a grid containing a various number of rectangles in JavaFX. It is important that this grid cannot be resized.

我想在 JavaFX 中显示包含各种矩形的网格。不能调整此网格的大小很重要。

I chose the GridPanelayout. I dynamically add javafx.scene.shape.Rectangleto it. Here's how my grid looks like with 2 rows and 4 columns.

我选择了GridPane布局。我动态添加javafx.scene.shape.Rectangle到它。这是我的网格 2 行 4 列的样子。

Upon resizing, I would like it to keep the same overall shape, that is to say each Rectanglehaving the same size and keeping an horizontal and vertical gaps between my Rectangles.

调整大小时，我希望它保持相同的整体形状，也就是说每个都Rectangle具有相同的大小并在我的Rectangles之间保持水平和垂直间隙。

However, here's what I get with a 4x4 grid:

但是，这是我使用 4x4 网格得到的结果：

The problems being:

问题在于：

• The last row and last column do not have the same size as the rest of the Rectangles.
• The gaps have disappeared.

• 最后一行和最后一列的大小与Rectangles的其余部分不同。
• 缝隙已经消失。

Here is my code responsible for refreshing the display:

这是我负责刷新显示的代码：

public void refreshConstraints() {
    getRowConstraints().clear();
    getColumnConstraints().clear();

    for (int i = 0; i < nbRow; i++) {
        RowConstraints rConstraint = new RowConstraints();
        // ((nbRow - 1) * 10 / nbRow) = takes gap into account (10% of height)
        rConstraint.setPercentHeight(100 / nbRow - ((nbRow - 1) * 10 / nbRow));
        getRowConstraints().add(rConstraint);
    }

    for (int i = 0; i < nbColumn; i++) {
        ColumnConstraints cConstraint = new ColumnConstraints();
        cConstraint.setPercentWidth(100 / nbColumn - ((nbColumn - 1) * 10 / nbColumn));
        getColumnConstraints().add(cConstraint);
    }

}

Using the setFillWidthand setHgrowyields no result either, the gap is kept between my Rectangles, but the Rectangles aren't resized and they overlap the rest of my GUI elements.

使用setFillWidth和 也setHgrow不会产生任何结果，我的Rectangles之间保留了间隙，但Rectangles 没有调整大小，并且它们与我的其余 GUI 元素重叠。

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EDIT: MCVE code:

编辑：MCVE 代码：

import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.ColumnConstraints;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.RowConstraints;
import javafx.scene.paint.Paint;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

public class DynamicGrid extends Application {

    //Class containing grid (see below)
    private GridDisplay gridDisplay;

    @Override
    public void start(Stage primaryStage) {

        //Represents the grid with Rectangles
        gridDisplay = new GridDisplay(400, 200);

        //Fields to specify number of rows/columns
        TextField rowField = new TextField();
        TextField columnField = new TextField();
        //Function to set an action when text field loses focus
        buildTextFieldActions(rowField, columnField);
        HBox fields = new HBox();
        fields.getChildren().add(rowField);
        fields.getChildren().add(new Label("x"));
        fields.getChildren().add(columnField);

        BorderPane mainPanel = new BorderPane();
        mainPanel.setLeft(gridDisplay.getDisplay());
        mainPanel.setBottom(fields);

        Scene scene = new Scene(mainPanel);
        primaryStage.setTitle("Test grid display");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

    private void buildTextFieldActions(final TextField rowField, final TextField columnField) {
        rowField.focusedProperty().addListener(new ChangeListener<Boolean>() {

            @Override
            public void changed(ObservableValue<? extends Boolean> ov, Boolean t, Boolean t1) {
                if (!t1) {
                    if (!rowField.getText().equals("")) {
                        try {
                            int nbRow = Integer.parseInt(rowField.getText());
                            gridDisplay.setRows(nbRow);
                            gridDisplay.updateDisplay();
                        } catch (NumberFormatException nfe) {
                            System.out.println("Please enter a valid number.");
                        }
                    }
                }
            }
        });

        columnField.focusedProperty().addListener(new ChangeListener<Boolean>() {

            @Override
            public void changed(ObservableValue<? extends Boolean> ov, Boolean t, Boolean t1) {
                if (!t1) {
                    if (!columnField.getText().equals("")) {
                        try {
                            int nbColumn = Integer.parseInt(columnField.getText());
                            gridDisplay.setColumns(nbColumn);
                            gridDisplay.updateDisplay();
                        } catch (NumberFormatException nfe) {
                            System.out.println("Please enter a valid number.");
                        }
                    }
                }
            }
        });
    }

    //Class responsible for displaying the grid containing the Rectangles
    public class GridDisplay {

        private GridPane gridPane;
        private int nbRow;
        private int nbColumn;
        private int width;
        private int height;
        private double hGap;
        private double vGap;

        public GridDisplay(int width, int height) {
            this.gridPane = new GridPane();
            this.width = width;
            this.height = height;
            build();
        }

        private void build() {
            this.hGap = 0.1 * width;
            this.vGap = 0.1 * height;
            gridPane.setVgap(vGap);
            gridPane.setHgap(hGap);
            gridPane.setPrefSize(width, height);
            initializeDisplay(width, height);
        }

        //Builds the first display (correctly) : adds a Rectangle for the number
        //of rows and columns
        private void initializeDisplay(int width, int height) {
            nbRow = height / 100;
            nbColumn = width / 100;

            for (int i = 0; i < nbColumn; i++) {
                for (int j = 0; j < nbRow; j++) {
                    Rectangle rectangle = new Rectangle(100, 100);
                    rectangle.setStroke(Paint.valueOf("orange"));
                    rectangle.setFill(Paint.valueOf("steelblue"));
                    gridPane.add(rectangle, i, j);

                }
            }
        }

        //Function detailed in post
        //Called in updateDisplay()
        public void refreshConstraints() {
            gridPane.getRowConstraints().clear();
            gridPane.getColumnConstraints().clear();
            for (int i = 0; i < nbRow; i++) {
                RowConstraints rConstraint = new RowConstraints();
                rConstraint.setPercentHeight(100 / nbRow - ((nbRow - 1) * 10 / nbRow));
                gridPane.getRowConstraints().add(rConstraint);
            }

            for (int i = 0; i < nbColumn; i++) {
                ColumnConstraints cConstraint = new ColumnConstraints();
                cConstraint.setPercentWidth(100 / nbColumn - ((nbColumn - 1) * 10 / nbColumn));
                gridPane.getColumnConstraints().add(cConstraint);
            }

        }

        public void setColumns(int newColumns) {
            nbColumn = newColumns;
        }

        public void setRows(int newRows) {
            nbRow = newRows;
        }

        public GridPane getDisplay() {
            return gridPane;
        }

        //Function called when refreshing the display
        public void updateDisplay() {
            Platform.runLater(new Runnable() {

                @Override
                public void run() {
                    //The gridpane is cleared of the previous children
                    gridPane.getChildren().clear();

                    //A new rectangle is added for row*column
                    for (int i = 0; i < nbColumn; i++) {
                        for (int j = 0; j < nbRow; j++) {
                            Rectangle rectangle = new Rectangle(100, 100);
                            rectangle.setStroke(Paint.valueOf("orange"));
                            rectangle.setFill(Paint.valueOf("steelblue"));
                            gridPane.add(rectangle, i, j);
                        }
                    }
                    //Call to this function to update the grid's constraints
                    refreshConstraints();
                }
            });

        }

    }

}

采纳答案by Koln

Thanks a lot for your answer. TilePanes are indeed a lot easier to use, although what you've written does not completely answer my question.

非常感谢您的回答。TilePanes 确实更容易使用，尽管您所写的内容并没有完全回答我的问题。

I wanted to have a pane in which the childrenwould resize, and not the pane itself. It seems setting the maxSizeand prefSizedoesn't have any effect.

我想要一个窗格，孩子们可以在其中调整大小，而不是窗格本身。似乎设置maxSize和prefSize没有任何效果。

EDIT: I managed to do it using two JavaFX Propertyin my GridDisplayclass, corresponding to the fixed height and width of my grid:

编辑：我设法Property在我的GridDisplay班级中使用两个 JavaFX 来做到这一点，对应于我的网格的固定高度和宽度：

public class GridDisplay {
    private ReadOnlyDoubleProperty heightProperty;
    private ReadOnlyDoubleProperty widthProperty;

    ...
}

Then I assign to these members the values corresponding to the desired fixed size in the constructor. The size of the children inside the grid correspond to a fraction of the height and width of the grid, depending on the number of rows and columns. Here's what my updateDisplay()looks like:

然后我为这些成员分配与构造函数中所需的固定大小相对应的值。网格内子元素的大小对应于网格高度和宽度的一部分，具体取决于行数和列数。这是我的updateDisplay()样子：

public void updateDisplay() {
    gridPane.getChildren().clear();
    for (int i = 0; i < nbColumn; i++) {
        for (int j = 0; j < nbRow; j++) {
            Rectangle rectangle = new Rectangle(100, 100);
            //Binding the fraction of the grid size to the width
            //and heightProperty of the child
            rectangle.widthProperty().bind(widthProperty.divide(nbColumn));
            rectangle.heightProperty().bind(heightProperty.divide(nbRow));
            gridPane.add(rectangle, i, j);
         }
    }
}

回答by jewelsea

Seems like a TilePaneis a better fit for this use case than a GridPane.

似乎TilePane比 GridPane 更适合这个用例。

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.TilePane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

// java 8 code
public class DynamicTiles extends Application {

    //Class containing grid (see below)
    private GridDisplay gridDisplay;

    //Class responsible for displaying the grid containing the Rectangles
    public class GridDisplay {

        private static final double ELEMENT_SIZE = 100;
        private static final double GAP = ELEMENT_SIZE / 10;

        private TilePane tilePane = new TilePane();
        private Group display = new Group(tilePane);
        private int nRows;
        private int nCols;

        public GridDisplay(int nRows, int nCols) {
            tilePane.setStyle("-fx-background-color: rgba(255, 215, 0, 0.1);");
            tilePane.setHgap(GAP);
            tilePane.setVgap(GAP);
            setColumns(nCols);
            setRows(nRows);
        }

        public void setColumns(int newColumns) {
            nCols = newColumns;
            tilePane.setPrefColumns(nCols);
            createElements();
        }

        public void setRows(int newRows) {
            nRows = newRows;
            tilePane.setPrefRows(nRows);
            createElements();
        }

        public Group getDisplay() {
            return display;
        }

        private void createElements() {
            tilePane.getChildren().clear();
            for (int i = 0; i < nCols; i++) {
                for (int j = 0; j < nRows; j++) {
                    tilePane.getChildren().add(createElement());
                }
            }
        }

        private Rectangle createElement() {
            Rectangle rectangle = new Rectangle(ELEMENT_SIZE, ELEMENT_SIZE);
            rectangle.setStroke(Color.ORANGE);
            rectangle.setFill(Color.STEELBLUE);

            return rectangle;
        }

    }

    @Override
    public void start(Stage primaryStage) {

        //Represents the grid with Rectangles
        gridDisplay = new GridDisplay(2, 4);

        //Fields to specify number of rows/columns
        TextField rowField = new TextField("2");
        TextField columnField = new TextField("4");

        //Function to set an action when text field loses focus
        buildTextFieldActions(rowField, columnField);

        HBox fields = new HBox(10);
        fields.getChildren().add(rowField);
        fields.getChildren().add(new Label("x"));
        fields.getChildren().add(columnField);

        BorderPane mainPanel = new BorderPane();
        mainPanel.setCenter(gridDisplay.getDisplay());
        mainPanel.setTop(fields);

        Scene scene = new Scene(mainPanel, 1000, 800);
        primaryStage.setTitle("Test grid display");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

    private void buildTextFieldActions(final TextField rowField, final TextField columnField) {
        rowField.focusedProperty().addListener((ov, t, t1) -> {
            if (!t1) {
                if (!rowField.getText().equals("")) {
                    try {
                        int nbRow = Integer.parseInt(rowField.getText());
                        gridDisplay.setRows(nbRow);
                    } catch (NumberFormatException nfe) {
                        System.out.println("Please enter a valid number.");
                    }
                }
            }
        });

        columnField.focusedProperty().addListener((ov, t, t1) -> {
            if (!t1) {
                if (!columnField.getText().equals("")) {
                    try {
                        int nbColumn = Integer.parseInt(columnField.getText());
                        gridDisplay.setColumns(nbColumn);
                    } catch (NumberFormatException nfe) {
                        System.out.println("Please enter a valid number.");
                    }
                }
            }
        });
    }
}