对嵌入在 html 中的 Applet 施加大小限制 [英] Force size restrictions on Applet embedded in html
问题描述
我有一个带有 GridLayout 的 Java Applet，其中包含我希望是方形的小部件，并保持彼此紧密包装(因此它们的大小不受限制).
但是，我希望 GridLayout 在屏幕过大或无法保留小部件方形"之前占用尽可能多的空间.
注意GridLayout中的行数和列数不一定相等(Grid作为一个整体可以是非正方形的)
I have a Java Applet with a GridLayout containing widgets which I wish to be square, and remain tightly packed to each other (so their sizes are unrestricted).
However, I wish for the GridLayout to take up as much space as possible before being too large for the screen or unable to preserve widget 'squareness'.
Note that the number of rows and columns in the GridLayout are not necessarily equal (the Grid as a whole can be non-square)
这个Applet是通过这个html文件显示的；
This Applet is displayed via this html file;
<html>
<body>
<applet code=client.Grid.class
archive="program.jar"
width=100% height=95%>
</applet>
</body>
</html>
目前，这会使 Applet 扩展到它所在的窗口中；可以通过调整窗口大小来调整网格的大小，但这会导致每个小部件的几何形状发生变化(失去平方").
Currently, this makes the Applet expand into the window it is put in; the Grid can be resized by resizing the window, but this causes the geometry of each widget to be changed (losing 'squaredness').
所以；我在哪里以及如何放置这些几何限制?
它不能单独存在于 html 文件中，因为它不知道行/列数，因此不知道制作 Applet 的最佳大小.
但是，我不知道如何在 GridLayout 或包含它的面板上设置大小，因为它必须知道查看浏览器的页面大小(使其尽可能大)并且我的印象是 html指定的几何图形覆盖指定的 Applet.
So; where and how do I place these geometrical restrictions?
It can't be in the html file alone, since it has no knowledge of row/column count, and so doesn't know the best size to make the Applet.
However, I don't know how to set the size on the GridLayout or the Panel containing it, since it must know the viewing-browser's page size (to make it as large as possible) and I'm of the impression that the html specified geometry overrides the Applet specified.
试图实施安德鲁的建议；
Attempting to implement Andrew's suggestion;
screen = new JPanel(new GridLayout(rows, columns)) {
public Dimension getPreferredSize() {
Dimension expected = super.getPreferredSize();
// calculate preferred size using expected, rows, columns
return new Dimension(100, 100) // testing
}
public Dimension getSize() {
return getPreferredSize();
}
};
我知道这忽略了最小尺寸"的内容，但目前这无关紧要.
屏幕放置在边框布局的中心，包含其他小部件
I understand this ignores the 'minimum size' stuff, but that doesn't matter at the moment.
Screen is placed in the center of a border layout, containing other widgets
getContentPane().add(screen, BorderLayout.CENTER);
getContentPane().add(otherWidgets, BorderLayout.PAGE_END);
我知道这不会使 screen 在它所拥有的空间中居中，但目前这不是完全必要的，所以我想让事情尽可能简单.
I know this doesn't make screen centered in the space it has, but that's not entirely necessary at the moment so I want to keep things as simple as possible.
这根本行不通；除了最小尺寸的东西外，与我之前的(通过 Eclipse 查看时；我什至还没有达到 html 阶段)没有明显的区别.屏幕组件仍在空闲时由小程序重新调整大小，使单元格不方形".我做错了什么?
This isn't at all working; there's no visible difference from what I had before (when viewed through Eclipse; I haven't even reached the html stage yet) excepting the minimum size stuff. The screen component is still being re-sized by the applet at leisure, making the cells 'unsquare'. What am I doing wrong?
推荐答案
将网格布局容器作为唯一没有约束的组件放入网格包布局中，见这个答案.这将使其居中.
Put the grid layout container into a grid bag layout as the only component with no constraint, as seen in this answer. That will center it.
当然，将它放在一个组件中，该组件返回一个首选大小，该大小等于它可以根据父级大小管理的最大正方形大小.如SquarePanel.
And of course, put it in a component that returns a preferred size equating to the maximum square size it can manage depending on the parent size. Such as in SquarePanel.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
/**
* A square panel for rendering. NOTE: To work correctly, this must be the only
* component in a parent with a layout that allows the child to decide the size.
*/
class SquarePanel extends JPanel {
@Override
public Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
System.out.println("Preferred Size: " + d);
int w = (int) d.getWidth();
int h = (int) d.getHeight();
// Set s to the larger of the mimimum component width or height
int s = (w > h ? w : h);
Container c = getParent();
if (c != null ){
Dimension sz = c.getSize();
if ( d.getWidth()<sz.getWidth() ) {
// Increase w to the size available in the parent container
w = (int)sz.getWidth();
System.out.println("WxH: " + w + "x" + h);
// recalculate s
s = (w < h ? w : h);
}
if ( d.getHeight()<sz.getHeight()) {
// Increase h to the size available in the parent container
h = (int)sz.getHeight();
System.out.println("WxH: " + w + "x" + h);
// recalculate s
s = (w < h ? w : h);
}
}
// Use s as the basis of a square of side length s.
System.out.println("Square Preferred Size: " + new Dimension(s, s));
return new Dimension(s, s);
}
@Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
@Override
public Dimension getSize() {
return getPreferredSize();
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
// the GUI as seen by the user (without frame)
// A single component added to a GBL with no constraint
// will be centered.
JPanel gui = new JPanel(new GridBagLayout());
gui.setBackground(Color.BLUE);
SquarePanel p = new SquarePanel();
p.setBorder(new EmptyBorder(5,15,5,15));
p.setLayout(new GridLayout(3,0,2,2));
for (int ii=1; ii<13; ii++) {
p.add(new JButton("" + ii));
}
p.setBackground(Color.red);
gui.add(p);
JFrame f = new JFrame("Demo");
f.add(gui);
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
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