它展示了什么
The same items as cards or as a table, with the reader choosing — and a frozen first column.
在你的机器上运行
每个示例都是普通的 Window,启动器只需要它的名字。
gradlew lwjgl3:run --args="classname dev.cf.recipe.R05Listing"修改它
Java 是提前编译的,浏览器无法自行重建你的修改 —— 这里的代码在发布前已由 TeaVM 转成 JavaScript。把文件复制到项目里,它在四个平台上原样运行;上面那条命令就是全部准备工作。
它用到了什么
本示例触及的框架类型。带链接的有参考页。
CardComponentDataGridGridLayoutListingStylesVerticalLayoutWidgets
源码
完整无删减。这就是那个文件,不是片段。
dev/cf/recipe/R05Listing.java
package dev.cf.recipe;
import dev.cf.Tones;
import dev.crossfly.ui.*;
import dev.crossfly.ui.color.*;
import dev.crossfly.ui.graphics.*;
import dev.crossfly.ui.layout.*;
import dev.crossfly.ui.style.*;
import static dev.crossfly.ui.Widgets.*;
/**
* The same items as cards or as a table, with the reader choosing — and a frozen first column.
*/
public class R05Listing extends Recipe
{
// Brazilian company and city names, kept as sample data: proper names of a Brazilian client list
// (iniciais() below also relies on "Casa do Norte" having a preposition in the middle).
private static final String[] NOME ={ "Aurora Distribuidora", "Primavera Norte", "Vale Sul",
"Casa do Norte", "Mercantil Boa Vista", "Atacado Serra", "Comercial Ipê" };
private static final String[] CIDADE = { "Campinas", "Sumaré", "Indaiatuba", "Jundiaí",
"Valinhos", "Vinhedo", "Itu" };
private static final int[] VALOR = { 12400, 8300, 21750, 4120, 15990, 6480, 9310 };
public String title()
{
return "Listing: cards or table";
}
public String note()
{
return "A card answers \"what is this one?\"; a row answers \"how do these compare?\". Which"
+ " one the reader needs changes during the day, so Listing lets them switch.";
}
public void build(Component body) throws Exception
{
Listing lista = new Listing().cardWidth(20f)
.columns(1, 3)
.column("nome", "Client", 13f)
.column("cidade", "City", 9f)
.column("valor", "Amount", 8f, Position.END)
// The frozen column does not leave the view when the table scrolls horizontally — it is
// what tells whose row you are reading out at the far right.
.freeze(Position.START, "nome")
.items(new Listing.Items()
{
public int count()
{
return NOME.length;
}
public Component card(int i) throws Exception
{
// Tile on the left, the three lines on the right. A column of name-over-city-over-
// value is three greys with nothing for the eye to land on between rows; the tile
// is one line of code and it is what makes the list scannable.
Card c = new Card();
c.setLayout(new GridLayout(Position.START, Position.CENTER));
Component texto = new Component();
texto.setLayout(new VerticalLayout(Position.START, Position.START));
texto.add(LAY_AUTO, label(NOME[i], 1.2f, true, Styles.textColor, Position.START));
texto.add(LAY_AUTO, label(CIDADE[i], 1f, false, Styles.captionColor,
Position.START));
texto.add(LAY_AUTO, outgap(label(valor(i), 1.1f, true, Tones.accent(),
Position.START), 0, .15f, 0, 0));
c.add(LAY_AUTO, 1f, Tones.tile(iniciais(i), Tones.cycle(i)),
outgap(texto, .6f, 0, 0, 0));
return c;
}
public void row(DataGrid.Row r, int i) throws Exception
{
r.cell(0, label(NOME[i], 1f, true, Styles.textColor, Position.START));
r.cell(1, label(CIDADE[i], 1f, false, Styles.captionColor, Position.START));
// The amount is what the table exists to compare, so it is the one coloured cell.
r.cell(2, label(valor(i), 1f, true, Tones.accent(), Position.END));
}
});
lista.testTag("recipe.listing");
// The switch has to be placed by the SCREEN. Listing offers modeButton() and never draws it
// itself, because a listing usually sits under a toolbar that already has a count and a sort
// control, and a bar of its own would be a second one. Leave this line out and the recipe
// shows cards with no way to reach the table — which is what it did until somebody looked.
Component barra = new Component();
barra.setLayout(new GridLayout(Position.START, Position.CENTER));
barra.add(1f, 0f, label("7 clients", 1f, false, Styles.captionColor, Position.START),
lista.modeButton());
body.add(LAY_AUTO, outgap(barra, 0, 0, 0, .5f));
body.add(LAY_FILL, lista);
}
/** The first letter of each of the first two words — "Aurora Distribuidora" becomes AD. */
private static String iniciais(int i)
{
String[] p = NOME[i].split(" ");
// Upper case both, or "Casa do Norte" answers "Cd" — the second word is a preposition and
// the tile ends up shouting the one letter that carries no information.
return p.length > 1 ? ("" + p[0].charAt(0) + p[p.length - 1].charAt(0)).toUpperCase()
: p[0].substring(0, 2).toUpperCase();
}
private static String valor(int i)
{
return "R$ " + VALOR[i] / 100 + "," + (VALOR[i] % 100 < 10 ? "0" : "") + VALOR[i] % 100;
}
}dev/cf/recipe/Recipe.java
package dev.cf.recipe;
import dev.cf.*;
import dev.crossfly.ui.*;
import dev.crossfly.ui.graphics.*;
import dev.crossfly.ui.layout.*;
import dev.crossfly.ui.skin.*;
import dev.crossfly.ui.style.*;
import static dev.crossfly.ui.Widgets.*;
/**
* Base of a <b>recipe</b>: one screen that shows one thing, and nothing else.
*
* <p>A recipe is not a sample. A sample shows a component with all its knobs; a recipe answers a
* question somebody actually has — "how do I put a filter sheet over a list?", "how do I make this
* follow the theme?" — in as few lines as it takes, so the answer can be read in one screen and
* copied without editing.</p>
*
* <p>That is the whole design constraint: <b>the boilerplate lives here, the substance lives in the
* subclass.</b> A recipe that spends twenty lines building a title bar teaches the title bar.</p>
*
* <p>Write one as:</p>
*
* <pre>
* public class MyRecipe extends Recipe
* {
* public String title() { return "What this shows"; }
* public String note() { return "The one sentence worth knowing."; }
*
* public void build(Component body) throws Exception
* {
* body.add(LAY_AUTO, new Button("Tap"));
* }
* }
* </pre>
*/
public abstract class Recipe extends SampleWindow implements Described
{
@Override
public abstract String title();
/**
* The one thing a reader should take away — printed above the recipe, in caption tone.
*
* @return the note, or null for none
*/
@Override
public String note()
{
return null;
}
/**
* Builds the recipe.
*
* @param body a vertical, scrollable container with sensible padding — add to it and stop
* @throws Exception when building fails
*/
public abstract void build(Component body) throws Exception;
@Override
public void onAdd(boolean firstTime) throws Exception
{
addTopBar(title());
// The page, not the surface. addTopBar just set fullscreenColor to the surface,
// and on a white page a white card has no edges — see Tones.page(). Re-derived on restyle so
// a dark-mode flip does not leave the light page behind.
fullscreenColor = Tones.page();
onRestyle(() -> fullscreenColor = Tones.page());
contents.setLayout(new VerticalLayout(Position.START, Position.START));
contents.getStyle()
.ingap(Gap.ofFont(1f, 1f, 1f, 1f));
String n = note();
if (n != null)
contents.add(LAY_AUTO, outgap(nota(n), 0, 0, 0, 1f));
Component body = new Component();
body.setLayout(new VerticalLayout(Position.START, Position.START));
body.setScrollable(ScrollDirection.VERTICAL);
body.testTag("recipe.body");
contents.add(LAY_FILL, body);
build(body);
if (pinned != null)
{
// Measured again once its labels have sizes: the band's AUTO height is taken in the first
// layout, before them, and on the iPhone it showed only its first line - the odometer's
// "No text recognizer on this device." was set and never seen (17/10/2026).
final Component band = pinned;
onUI(band::invalidateMeasure);
}
if (pinned != null)
body.add(LAY_AUTO, new Component()
{
@Override
public int getAutoHeight()
{
// Room for the last row to scroll clear of the floating band.
return pinned.getAutoHeight();
}
});
}
/**
* The note, as a tinted band rather than three lines of grey.
*
* <p>It is the one sentence the reader is meant to leave with, and it used to be the least
* legible thing on the screen: caption-coloured, caption-sized, indistinguishable from the
* captions further down that are only labels. A tone and a glyph cost nothing here — nobody has
* to read the band to know what it is.</p>
*
* @param n the note text
* @return the band
* @throws Exception when building fails
*/
/**
* Pins {@code c} to the bottom of the screen, in a band that FLOATS over the scrolling body: it
* stays on screen however far the body is scrolled, and the body scrolls underneath it. That is the
* place a recipe says what just happened. An answer at the top of the body went out of view as soon
* as the person scrolled down to the button that produced it (14/10/2026).
* <p>
* The band is 80% OPAQUE (the surface at alpha 0xCC), as the user asked; it floats rather than
* sitting below the body because a transparency with nothing behind it cannot be seen -- the first
* version had the band under the body, and the person saw a plain bar. The body gets a spacer as
* tall as the band at its end, so its last row can still scroll clear of it.
*
* @param c the component to pin, usually the answer label
* @return {@code c}, to chain
* @throws Exception if the layout refuses
*/
protected <T extends Component> T pin(T c) throws Exception
{
Component band = new Component();
band.setLayout(new VerticalLayout(Position.START, Position.START));
band.style(Skin.get()
.card()
.backColor(Styles.backColor.withAlpha(0xCC))
.borderColor(Styles.borderColor.withAlpha(0x33))
.borderRadius(0)
.shadow(0, 0, 0, 0)
.ingap(Gap.ofFont(1f, 1f, 1f, 1.2f))
.outgap(Gap.ofFont(0)));
band.add(LAY_AUTO, c);
// Floated: positioned at the bottom, full width, over whatever the body has there.
band.setRelativeBounds(Relative.START, Relative.END, Relative.FULL, Relative.AUTO);
contents.add(LAY_AUTO, band);
pinned = band;
return c;
}
/** The floating band {@link #pin} made, or null; the body ends in a spacer as tall as it. */
private Component pinned;
private Component nota(String n) throws Exception
{
Component band = new Component();
band.setLayout(new GridLayout(Position.START, Position.START));
band.style(Skin.get()
.card()
.backColor(Tones.accent().withAlpha(0x16))
.borderColor(Tones.accent().withAlpha(0x4A))
.shadow(0, 0, 0, 0)
.outgap(Gap.ofFont(0)));
// 0xE88E is the outlined "info". The glyph column hugs; the text takes the rest and wraps.
// The weights are GridLayout's own — 0f hugs, 1f takes what is left. LAY_FILL belongs to the
// vertical and horizontal layouts and means nothing here: it collapsed the text to nothing.
band.add(LAY_AUTO, 1f, matglyph(0xE88E, Tones.accent(), 1.05f),
outgap(label(n, 1f, false, secondary(), Position.START), .5f, 0, 0, 0));
return band;
}
}dev/cf/SampleWindow.java
package dev.cf;
import dev.crossfly.ui.*;
import dev.crossfly.ui.graphics.*;
import dev.crossfly.ui.layout.*;
import dev.crossfly.ui.style.*;
import static dev.cf.sample.CrossFlySamplesColors.*;
/**
* Base class for all CrossFly sample windows.
* <p>
* Provides common infrastructure:
* <ul>
* <li>Shared color palette and styles from {@link dev.cf.sample.CrossFlySamplesColors}</li>
* <li>{@link #addTopBar(String, Button...)} — standard deep-indigo top bar with back button</li>
* <li>{@link #barButton(String, Runnable)} — helper to create icon buttons for the bar</li>
* </ul>
*
* <h3>Usage</h3>
* <pre>
* public class MySample extends SampleWindow {
* public void onAdd(boolean firstTime) throws Exception {
* if (!firstTime) return;
* initWindow();
* addTopBar("My Sample");
* // ... add content
* }
* }
* </pre>
*/
public abstract class SampleWindow extends Window
{
/** The main content area of the window, added by {@link #addTopBar(String, Button...)}, for subclasses to add their content into. */
protected Component contents;
// ─── Top bar ─────────────────────────────────────────────────────────────
/**
* Builds and adds a standard top bar with a back (←) button on the left,
* a centered title, and any optional extra buttons on the right.
*
* @param title the text shown in the bar
* @param rightButtons zero or more icon buttons placed aligned to the right
* @throws Exception if component construction fails
*/
protected void addTopBar(String title, Button... rightButtons) throws Exception
{
fullscreenColor = Styles.backColor.color();
setLayout(new VerticalLayout());
add(0f, buildTopBar(title, rightButtons));
add(LAY_FILL, contents = new Component());
contents.getStyle()
.ingap(Gap.ofFont(0, .5f, 0, .5f));
}
/**
* Same as {@link #addTopBar(String, Button...)}, but returns the bar component
* instead of adding it, for callers that need to position it manually.
*
* @param title the bar title
* @param rightButtons optional right-side icon buttons
* @return the assembled top-bar {@link Component}
* @throws Exception if component construction fails
*/
protected Component buildTopBar(String title, Button... rightButtons) throws Exception
{
Button btBack = barButton("\ue5c4", this::hide); // arrow_back
btBack.testTag("sample.back");
// Padded on every side, like the bar's right buttons: with none above and below, the target
// was the arrow itself, too small to hit on a small phone (iPhone 5s, 17/10/2026).
btBack.getStyle()
.ingap(Gap.ofFont(.75f))
.outgap(Gap.ofFont(0, 0, .25f, 0));
Component bar = new Component().style(barStyle);
bar.setLayout(new GridLayout(Position.START, Position.CENTER));
int n = 2 + rightButtons.length;
Object[] params = new Object[n * 2];
params[0] = 0f;
params[1] = 1f;
for (int i = 0; i < rightButtons.length; i++)
params[2 + i] = 0f;
params[n] = btBack;
params[n + 1] = new Label(title).style(barTitleStyle);
for (int i = 0; i < rightButtons.length; i++)
{
params[n + 2 + i] = rightButtons[i];
rightButtons[i].getStyle()
.ingap(Gap.ofFont(.75f));
}
bar.add(params);
return bar;
}
/**
* Creates a standard bar icon button (transparent, white icon, pressed feedback).
*
* @param materialIcon the Material Icon unicode codepoint string
* @param action the action to run when the button is tapped
* @return the configured {@link Button}
*/
protected Button barButton(String materialIcon, Runnable action)
{
return new Button(new MaterialIcon(materialIcon)).style(barButtonNormal)
.pressedStyle(barButtonPressed)
.onAction(e -> action.run());
}
}给 AI 助手
本页的机器可读版本,让模型直接读取示例集,而不是猜测 API。