Java UndoManager类代码示例

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
/**
 * Reload the content.
 *
 * @param content      the content.
 * @param clearHistory true if need to clear history.
 */
@FXThread
public void reloadContent(@NotNull final String content, final boolean clearHistory) {

    final String currentContent = getText();

    if (!StringUtils.equals(currentContent, content)) {
        if (content.isEmpty()) {
            try {
                clear();
            } catch (final IllegalStateException e) {
                //FIXME it's a bug in the richfxeditor library
                e.printStackTrace();
            }
        } else {
            replaceText(0, currentContent.length(), content);
        }
    }

    if (clearHistory) {
        final UndoManager undoManager = getUndoManager();
        undoManager.forgetHistory();
    }
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testUndoInvertsTheChange() {
    EventSource<Integer> changes = new EventSource<>();
    Var<Integer> lastAction = Var.newSimpleVar(null);
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes, i -> -i, i -> { lastAction.setValue(i); changes.push(i); });

    changes.push(3);
    changes.push(7);
    assertNull(lastAction.getValue());

    um.undo();
    assertEquals(-7, lastAction.getValue().intValue());

    um.undo();
    assertEquals(-3, lastAction.getValue().intValue());

    um.redo();
    assertEquals(3, lastAction.getValue().intValue());

    um.redo();
    assertEquals(7, lastAction.getValue().intValue());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testMark() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.fixedSizeHistoryUndoManager(
            changes, c -> c, changes::push, 4);

    assertTrue(um.atMarkedPositionProperty().get());
    changes.push(1);
    assertFalse(um.atMarkedPositionProperty().get());
    changes.push(2);
    um.mark();
    assertTrue(um.atMarkedPositionProperty().get());
    changes.push(3);
    changes.push(4);
    assertFalse(um.atMarkedPositionProperty().get());
    um.undo();
    um.undo();
    assertTrue(um.atMarkedPositionProperty().get());
    changes.push(3);
    changes.push(4);
    changes.push(5); // overflow
    changes.push(6);
    assertFalse(um.atMarkedPositionProperty().get());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
/**
 * Tests that isAtMarkedPosition() forces atMarkedPositionProperty()
 * become valid.
 */
@Test
public void testAtMarkedPositionRevalidation() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.zeroHistoryUndoManager(changes);

    um.atMarkedPositionProperty().get(); // atMarkedPositionProperty is now valid

    // we are going to expect two invalidations
    CountDownLatch latch = new CountDownLatch(2);
    um.atMarkedPositionProperty().addListener(observable -> latch.countDown());

    changes.push(1); // atMarkedPositionProperty has been invalidated
    assertEquals(1, latch.getCount());

    um.isAtMarkedPosition(); // we want to test whether this caused revalidation of atMarkedPositionProperty

    changes.push(2); // should have caused invalidation of atMarkedPositionProperty
    assertEquals(0, latch.getCount());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testPushedNonIdentityChangeIsStored() {
    SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes,
            i -> -i,    // invert
            i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received
            (a, b) -> Optional.of(a + b), // merge adds two changes together
            i -> i == 0); // identity change = 0

    changes.push(4);
    assertTrue(um.isUndoAvailable());
    um.undo();
    assertEquals(-4, lastAppliedValue.get());
    assertFalse(um.isUndoAvailable());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testPushedIdentityChangeIsNotStored() {
    SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes,
            i -> -i,    // invert
            i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received
            (a, b) -> Optional.of(a + b), // merge adds two changes together
            i -> i == 0); // identity change = 0

    // force lastAppliedValue to store non-zero value
    changes.push(4);
    um.undo();

    // test that pushed identity change is not stored
    changes.push(0);
    assertFalse(um.isUndoAvailable());
    assertEquals(-4, lastAppliedValue.get());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testMergeResultingInNonIdentityChangeStoresMergeAndPreventsNextMerge() {
    SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes,
            i -> -i,    // invert
            i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received
            (a, b) -> Optional.of(a + b), // merge adds two changes together
            i -> i == 0); // identity change = 0

    changes.push(1);
    changes.push(2);
    assertTrue(um.isUndoAvailable());
    um.undo();
    assertFalse(um.isUndoAvailable());
    assertEquals(-3, lastAppliedValue.get());

    um.redo(); // redo to test whether merge occurs on next push
    changes.push(5);
    assertTrue(um.isUndoAvailable());
    um.undo();
    assertEquals(-5, lastAppliedValue.get());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
/**
 * Load the content.
 *
 * @param content the content.
 */
@FXThread
public void loadContent(@NotNull final String content) {
    appendText(content);

    final UndoManager undoManager = getUndoManager();
    undoManager.forgetHistory();
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
protected void callUndoManagers(Consumer<UndoManager> umConsumer) {
	umConsumer.accept(pageChangeUndoManager);
	modelPageEditors.values().forEach(meps -> {
		ModelPageEditorSupplier mepSupplier = (ModelPageEditorSupplier) meps;
		if (mepSupplier.modelPageEditor != null) {
			umConsumer.accept(mepSupplier.get().getUndoManager());
		}
	});
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
private UndoManager newPageChangeUndoManager() {
	 UndoManager result = UndoManagerFactory.unlimitedHistoryUndoManager(
									pageChanges, // stream of changes to observe
									c -> c.invert(), // function to invert a change
									c -> c.apply(), // function to apply a change
									(c1, c2) -> c1.mergeWith(c2));
	 return result;
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testPositionValidAfterAddingAChange() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(changes, c -> c, changes::push);

    changes.push(1);
    UndoPosition pos = um.getCurrentPosition();
    changes.push(1);
    assertTrue(pos.isValid());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testPositionInvalidAfterMerge() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes, c -> -c, changes::push, (c1, c2) -> Optional.of(c1 + c2));

    changes.push(1);
    UndoPosition pos = um.getCurrentPosition();
    changes.push(1);
    assertFalse(pos.isValid());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void testRedoUnavailableAfterAnnihilation() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes, c -> -c, changes::push, (c1, c2) -> Optional.of(c1 + c2), c -> c == 0);

    changes.push(1);
    changes.push(-1);
    assertFalse(um.isRedoAvailable());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test
public void zeroHistoryUndoManagerMark() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.zeroHistoryUndoManager(changes);

    assertTrue(um.atMarkedPositionProperty().get());
    changes.push(1);
    assertFalse(um.atMarkedPositionProperty().get());
    changes.push(2);
    um.mark();
    assertTrue(um.atMarkedPositionProperty().get());
    changes.push(3);
    changes.push(4);
    assertFalse(um.atMarkedPositionProperty().get());
}
 

import org.fxmisc.undo.UndoManager; //导入依赖的package包/类
@Test(expected = IllegalStateException.class)
public void testFailFastWhenExpectedChangeNotReceived() {
    EventSource<Integer> changes = new EventSource<>();
    UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
            changes, i -> -i, i -> {});

    changes.push(1);

    um.undo(); // should throw because the undone change is not received back
}