使用GridLayout来创建一个智能布局，以响应正在调整大小的窗口？

Answer 1

我创建了一个示例Vaadin7 web应用程序，展示了GridLayout的两种用法。这两种用法都在布局的四个角中放置一个表和虚拟数据。当窗口的大小调整为较大或较小时，四个表相应地改变大小。

一种用法是由四个单元格、两列和两行组成的简单网格。另一种用法包括在中间一列和中间一行中有按钮的嵌套布局，在GridLayout中有三列和三行，总共有九个单元格，其中三个单元格为空。

每种用法的屏幕截图…

/**
 * 
 */
package com.example.quadrantgridlayout;

import com.vaadin.server.Sizeable;
import com.vaadin.ui.GridLayout;
import com.vaadin.ui.Table;

/**
 * An example use of GridLayout in Vaadin 7.1.
 * 
 * Each quadrant of the layout contains a table. Each table resizes in both width and height to fill any available space.
 * 
 * @author Basil Bourque
 * 
 *         Copyright © 2013 Basil Bourque.
 * 
 *         This example source code may be used freely forever by anyone taking full responsibility for doing so.
 * 
 */
public class QuadrantGridLayout extends GridLayout {

    /**
     * Constructor
     */
    public QuadrantGridLayout() {
        super();
        this.setMargin( true ); // Add space around the perimeter.
        this.setSpacing( true ); // Add space between widgets.

        // Make this Layout fill all available space in its container.
        // In this case its container is a UI.
        // In this case, that UI happens to fill its container, the web browser's tab/window.
        this.setWidth( 100, Sizeable.Unit.PERCENTAGE );
        this.setHeight( 100, Sizeable.Unit.PERCENTAGE );

        // Create four cells for our four tables.
        this.setColumns( 2 );
        this.setRows( 2 );

        // Create widgets.
        Table upperLeft = new AstronomersTable( "Upper Left " + new java.util.Date() ); // In real work I would use Joda Time, not j.u.Date.
        Table upperRight = new AstronomersTable( "Upper Right" );

        Table lowerLeft = new AstronomersTable( "Lower Left" );
        Table lowerRight = new AstronomersTable( "Lower Right" );

        // Compose layout.
        upperLeft.setWidth( 100, Sizeable.Unit.PERCENTAGE );
        upperLeft.setHeight( 100, Sizeable.Unit.PERCENTAGE );
        this.addComponent( upperLeft );

        upperRight.setSizeFull(); // Alternate syntax for setting both width and height to 100%, instead of two lines seen earlier above.
        this.addComponent( upperRight );

        // Cursor automatically moved to next row upon reaching the row's last cell.

        lowerLeft.setSizeFull();
        // lowerLeft.setHeight( 72 * 2, Sizeable.Unit.POINTS ); // Use this if you want to play with fixed sizing. 72 points per inch.
        this.addComponent( lowerLeft );

        lowerRight.setSizeFull();
        this.addComponent( lowerRight );

    }

}

/**
 * 
 */
package com.example.quadrantgridlayout;

import com.vaadin.server.Sizeable;
import com.vaadin.ui.Button;
import com.vaadin.ui.GridLayout;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.Table;
import com.vaadin.ui.VerticalLayout;

/**
 * An example use of GridLayout in Vaadin 7.1.
 * 
 * Each quadrant of the layout contains a table. Each table resizes in both width and height to fill any available space.
 * 
 * @author Basil Bourque
 * 
 *         Copyright © 2013 Basil Bourque.
 * 
 *         This example source code may be used freely forever by anyone taking full responsibility for doing so.
 */
public class QuadrantWithButtonsGridLayout extends GridLayout {

    /**
     * Constructor
     */
    public QuadrantWithButtonsGridLayout() {
        super();
        this.setMargin( true ); // Add space around the perimeter.
        this.setSpacing( true ); // Add space between widgets.

        // Make this Layout fill all available space in its container.
        // In this case its container is a UI.
        // In this case, that UI happens to fill its container, the web browser's tab/window.
        this.setWidth( 100, Sizeable.Unit.PERCENTAGE );
        this.setHeight( 100, Sizeable.Unit.PERCENTAGE );

        // Create 9 cells, like Tic-Tac-Toe. A table goes in each corner.
        this.setColumns( 3 );
        this.setRows( 3 );

        // Create tables.
        Table upperLeft = new AstronomersTable( "Upper Left " + new java.util.Date() ); // In real work I would use Joda Time, not j.u.Date.
        Table upperRight = new AstronomersTable( "Upper Right" );

        Table lowerLeft = new AstronomersTable( "Lower Left" );
        Table lowerRight = new AstronomersTable( "Lower Right" );

        // Create buttons, and collect into a Layout.
        Button alphaButton = new Button( "Alpha" );
        Button betaButton = new Button( "Beta" );
        VerticalLayout upperButtonsLayout = new VerticalLayout();
        upperButtonsLayout.setCaption( " " ); // Add an empty caption (Space character, actually) to force the buttons downwards to line up with tables.
        upperButtonsLayout.setSpacing( true ); // Add space between widgets.
        upperButtonsLayout.addComponent( alphaButton );
        upperButtonsLayout.addComponent( betaButton );

        Button gammaButton = new Button( "Gamma" );
        Button deltaButton = new Button( "Delta" );
        HorizontalLayout leftButtonsLayout = new HorizontalLayout();
        leftButtonsLayout.setSpacing( true );
        leftButtonsLayout.addComponent( gammaButton );
        leftButtonsLayout.addComponent( deltaButton );

        // Compose layout.

        // ----| ROW 1 |------------------------
        // Vaadin 6 & 7 seem to suffer a bug that makes one row wider than another despite being assigned the same ratio.
        // As a workaround, divide the wide column's ratio by half (give or take) to compensate.
        this.setRowExpandRatio( this.getCursorY(), 0.5F / 1.5F );
        // Column 1
        // Vaadin 6 & 7 seem to suffer a bug that makes one column wider than another despite being assigned the same ratio.
        // As a workaround, divide the wide column's ratio by half (or more) to compensate.
        this.setColumnExpandRatio( this.getCursorX(), 1F / 1.5F ); // Notice first argument is soft-coding the column position. Also, index (zero-based) counting .
        upperLeft.setWidth( 100, Sizeable.Unit.PERCENTAGE );
        upperLeft.setHeight( 100, Sizeable.Unit.PERCENTAGE );
        // upperLeft.setHeight( 72 * 2, Sizeable.Unit.POINTS ); // Use this if you want to play with fixed sizing. 72 points per inch.
        this.addComponent( upperLeft );

        // Column 2
        // should not expand or contract with window re-sizing. So set expansion ratio to zero.
        upperButtonsLayout.setSizeUndefined(); // Setting size to be "undefined" is the trick to getting this column to collapse to its own minimal size.
        this.addComponent( upperButtonsLayout );

        // Column 3
        this.setColumnExpandRatio( this.getCursorX(), 1F );
        upperRight.setSizeFull(); // Alternate syntax for setting both width and height to 100%, instead of two lines seen earlier above.
        this.addComponent( upperRight );
        // Cursor automatically moved to next row upon reaching the row's last cell.

        // ----| ROW 2 |------------------------
        // Column 1
        leftButtonsLayout.setSizeUndefined(); // Setting size to be "undefined" is the trick to getting this row to collapse to its own minimal size.
        this.addComponent( leftButtonsLayout );
        this.newLine(); // Move cursor to next row. We have nothing to place in the remaining two cells.

        // ----| ROW 3 |------------------------
        this.setRowExpandRatio( this.getCursorY(), 0.5F );
        // // Column 1
        lowerLeft.setSizeFull();
        this.addComponent( lowerLeft );

        // Column 2
        this.space(); // Move cursor to next cell. We have nothing to place in this middle cell.

        // Column 3
        lowerRight.setSizeFull();
        this.addComponent( lowerRight );

    }

}

package com.example.quadrantgridlayout;

import com.vaadin.server.VaadinRequest;
import com.vaadin.ui.Layout;
import com.vaadin.ui.TabSheet;
import com.vaadin.ui.UI;

/**
 * 
 * Main UI class
 * 
 * This example app demonstrates the use of GridLayout to build a smart resizing layout.
 * 
 * Built in Vaadin 7.1 (pre-release), but the GridLayout & Table portions should work in Vaadin 6 as well.
 * 
 * * @author Basil Bourque
 * 
 * Copyright © 2013 Basil Bourque.
 * 
 * This example source code may be used freely forever by anyone taking full responsibility for doing so.
 */
public class QuadrantGridLayoutUI extends UI {

    @Override
    protected void init( VaadinRequest request ) {
        // This app demonstrates two versions of a GridLayou made of quadrants, each containing a table.
        // The simpler version contains only the four tables.
        // The other version includes a middle column and row, each containing a Layout with buttons.
        final Layout layoutQuadrant = new QuadrantGridLayout();
        final Layout layoutQuadrantWithButtons = new QuadrantWithButtonsGridLayout();

        // Display content on screen.

        // If for simplicity you want to remove the TabSheet from the situation, swap this next line for all remaining code below.
        // this.setContent( layoutQuadrant ); // Copy-paste either Layout variable to try each version.

        TabSheet tabs = new TabSheet();
        tabs.setSizeFull(); // Make the TabSheet fill all available space. By default the height is fixed.
        tabs.addTab( layoutQuadrant, "Simple" );
        tabs.addTab( layoutQuadrantWithButtons, "With Buttons" );
        this.setContent( tabs );
    }

}

/**
 * 
 */
package com.example.quadrantgridlayout;

import com.vaadin.ui.Table;

/**
 * 
 * Creates a simple Vaadin table with some dummy data.
 * 
 * @author Basil Bourque
 * 
 *         Copyright © 2013 Basil Bourque, except where noted below.
 * 
 *         This source code may be used freely forever by anyone taking full responsibility for doing so.
 * 
 */
public class AstronomersTable extends Table {

    /**
     * 
     */
    public AstronomersTable() {
        super();
        this.configure();
    }

    /**
     * @param caption
     */
    public AstronomersTable( String caption ) {
        super( caption );
        this.configure();
    }

    private void configure() {
        // This method's source code taken from "The Book of Vaadin 7", plus I added an earlier astronomer.
        // https://vaadin.com/book/vaadin7/-/page/components.table.html

        // Configure options.
        this.setSelectable( true );

        /*
         * Define the names and data types of columns. The "default value" parameter is meaningless here.
         */
        this.addContainerProperty( "First Name", String.class, null );
        this.addContainerProperty( "Last Name", String.class, null );
        this.addContainerProperty( "Year", Integer.class, null );

        /* Add a few items in the this. */
        this.addItem( new Object[] { "Hypatia", "of Alexandria", new Integer( -370 ) }, new Integer( 1 ) );
        this.addItem( new Object[] { "Nicolaus", "Copernicus", new Integer( 1473 ) }, new Integer( 2 ) );
        this.addItem( new Object[] { "Tycho", "Brahe", new Integer( 1546 ) }, new Integer( 3 ) );
        this.addItem( new Object[] { "Giordano", "Bruno", new Integer( 1548 ) }, new Integer( 4 ) );
        this.addItem( new Object[] { "Galileo", "Galilei", new Integer( 1564 ) }, new Integer( 5 ) );
        this.addItem( new Object[] { "Johannes", "Kepler", new Integer( 1571 ) }, new Integer( 6 ) );
        this.addItem( new Object[] { "Isaac", "Newton", new Integer( 1643 ) }, new Integer( 7 ) );

    }

}