в 17:44, 31 мая 2010

2010-05-31T17:44:26Z

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== Copying Lists: public static void copy(List dest, List src) ==



<source lang="java">
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class MainClass {
public static void main(String[] a) {
List l1 = Arrays.asList(new String[] { "A", "B" ,"C"});
List l2 = Arrays.asList(new String[] { "A", "C", "D" });
Collections.copy(l1, l2); // works
Collections.copy(l2, l1); //
System.out.println(l1);
System.out.println(l2);
}
}</source>



<pre class=codeResult>[A, C, D]
[A, C, D]</pre>

== Create a List with a vertical ScrollBar and Add a bunch of items to it ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class ListCreateAddItemsToIt {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());

// Create a List with a vertical ScrollBar
List list = new List(shell, SWT.V_SCROLL);
// Add a bunch of items to it
for (int i = 0; i < 500; i++) {
list.add("A list item");
}

shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Create a multiple-selection list ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class CreateMultipleSelectionList {
// Strings to use as list items
private static final String[] ITEMS = { "A", "B", "C", "D" };
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
// Create a multiple-selection list
List multi = new List(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);

// Add the items, one by one
for (int i = 0, n = ITEMS.length; i < n; i++) {
multi.add(ITEMS[i]);
}

shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Create a single-selection list and add items ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class CreateSingleSelectionListAddItems {
// Strings to use as list items
private static final String[] ITEMS = { "A", "B", "C", "D" };
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
// Create a single-selection list
List single = new List(shell, SWT.BORDER | SWT.SINGLE | SWT.V_SCROLL);
// Add the items, one by one
for (int i = 0, n = ITEMS.length; i < n; i++) {
single.add(ITEMS[i]);
}
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Introducing List and List Styles ==

<p>List boxes display lists of strings and allow users to select one or more of them.</p>
StyleEffectSWT.BORDERDraws a border around this List.SWT.SINGLECreates a List that allows selection of only one item at a time. This is the default.SWT.MULTICreates a List that allows selection of multiple items at a time. You may specify only one of SWT.SINGLE or SWT.MULTI.SWT.H_SCROLLCreates a horizontal scrollbar to scroll this List.SWT.V_SCROLLCreates a vertical scrollbar to scroll this List.

== List Item Single Selection ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class ListItemSelection {
// Strings to use as list items
private static final String[] ITEMS = { "A", "B", "C", "D" };
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
// Create a single-selection list
List single = new List(shell, SWT.BORDER | SWT.SINGLE | SWT.V_SCROLL);
// Add the items, one by one
for (int i = 0, n = ITEMS.length; i < n; i++) {
single.add(ITEMS[i]);
}
// Select the third item
single.select(2);

shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Make List Scroll to the bottom ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class ListScrollBottom {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());

// Create a List with a vertical ScrollBar
List list = new List(shell, SWT.V_SCROLL);
// Add a bunch of items to it
for (int i = 0; i < 500; i++) {
list.add("A list item");
}
// Scroll to the bottom
list.select(list.getItemCount() - 1);
list.showSelection();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Multiple-Copy Collections ==

<p>The nCopies() method of Collections is similar to using fill(), then copy(), with a List:</p>



<source lang="java">
public static List nCopies(int n, Object element)</source>



<pre class=codeResult>[null, null, null, null, null, null, null, null, null, null]</pre>

== public static void fill(List list, Object element): method copies the same object reference to every element of the list ==



<source lang="java">
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class MainClass {
public static void main(String[] a) {
List list = new ArrayList(10);
Object anObject = "A";
list.add("N");
Collections.fill(list, anObject);
System.out.println(list);
System.out.println(list.size());
}
}</source>



<pre class=codeResult>[A]
1</pre>

== Reversing Lists: public static void reverse(List list) ==



<source lang="java">
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class MainClass {
public static void main(String[] a) {
List barFlies = Arrays.asList(new String[] { "A", "B", "C" });
Collections.reverse(barFlies);
System.out.println(barFlies);
}
}</source>



<pre class=codeResult>[C, B, A]</pre>

== Select a range ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class SelectRangeList {
// Strings to use as list items
private static final String[] ITEMS = { "A", "B", "C", "D" };
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
// Create a multiple-selection list
List multi = new List(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);

// Add the items all at once
multi.setItems(ITEMS);

// Select a range
multi.select(0, 2);

shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Setting Items: Add the items all at once ==



<source lang="java">
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
public class SettingItemsAddItemAtOnce {
// Strings to use as list items
private static final String[] ITEMS = { "A", "B", "C", "D" };
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
// Create a multiple-selection list
List multi = new List(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);

// Add the items all at once
multi.setItems(ITEMS);

shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>



== Shuffling Lists: randomly reorder the elements of a list ==



<source lang="java">
public static void shuffle(List list)
public static void shuffle(List list, Random rnd)</source>



<pre class=codeResult>[H, D, A, E, C, B, I]
[H, D, A, E, C, B, I]</pre>

== Sorting Lists: reordering the elements of a List ==



<source lang="java">
public static void sort(List list)
public static void sort(List list, Comparator comp)</source>



<pre class=codeResult>[A, B, C]</pre>

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в 17:44, 31 мая 2010

Admin: 1 версия