com.google.testing.testify.risk.frontend.client.view.widgets.EditableLabel.java Source code

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Here is the source code for com.google.testing.testify.risk.frontend.client.view.widgets.EditableLabel.java

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// Copyright 2010 Google Inc. All Rights Reseved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.testing.testify.risk.frontend.client.view.widgets;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.BlurEvent;
import com.google.gwt.event.dom.client.BlurHandler;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.DeckPanel;
import com.google.gwt.user.client.ui.FocusPanel;
import com.google.gwt.user.client.ui.HasText;
import com.google.gwt.user.client.ui.HasValue;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.Widget;

/**
 * Label which turns into an editable TextArea widget on click.
 *
 * @author chrsmith@google.com (Chris Smith)
 */
public class EditableLabel extends Composite implements HasText, HasValue<String> {

    interface EditableLabelUiBinder extends UiBinder<Widget, EditableLabel> {
    }

    private static final EditableLabelUiBinder uiBinder = GWT.create(EditableLabelUiBinder.class);

    @UiField
    public Label label;

    @UiField
    public TextBox textArea;

    @UiField
    public DeckPanel deckPanel;

    @UiField
    public FocusPanel focusPanel;

    private static final int LABEL_INDEX = 0;
    private static final int TEXTAREA_INDEX = 1;
    private boolean isReadOnly = false;

    public EditableLabel() {
        initWidget(uiBinder.createAndBindUi(this));

        deckPanel.showWidget(LABEL_INDEX);

        // When we receive focus, switch to edit mode.
        focusPanel.addFocusHandler(new FocusHandler() {
            @Override
            public void onFocus(FocusEvent event) {
                switchToEdit();
            }
        });

        // When the label is clicked, switch to edit mode.
        label.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                switchToEdit();
            }
        });

        // When focus leaves the text area, switch to display/readonly mode.
        textArea.addBlurHandler(new BlurHandler() {
            @Override
            public void onBlur(BlurEvent event) {
                switchToLabel();
            }
        });

        // On key Enter, commit the text and fire a change event.
        // On key Down, revert the text if the user presses escape.
        textArea.addKeyDownHandler(new KeyDownHandler() {
            @Override
            public void onKeyDown(KeyDownEvent event) {
                if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
                    switchToLabel();
                } else if (event.getNativeKeyCode() == KeyCodes.KEY_ESCAPE) {
                    textArea.setText(label.getText());
                    switchToLabel();
                }
            }
        });
    }

    /**
     * Sets the widget's ReadOnly flag, which prevents editing.
     */
    public void setReadOnly(boolean isReadOnly) {
        this.isReadOnly = isReadOnly;
        deckPanel.showWidget(0);
    }

    /** Switches the widget into 'Edit' mode. */
    public void switchToEdit() {
        if (isReadOnly || deckPanel.getVisibleWidget() == TEXTAREA_INDEX) {
            return;
        }

        textArea.setText(getValue());
        deckPanel.showWidget(TEXTAREA_INDEX);
        textArea.setFocus(true);
    }

    /** Switches the widget into 'Readonly' mode. */
    public void switchToLabel() {
        if (deckPanel.getVisibleWidget() == LABEL_INDEX) {
            return;
        }
        // Fires the ValueChanged event.
        setValue(textArea.getText(), true);
        deckPanel.showWidget(LABEL_INDEX);
    }

    // Implementation of HasValue<String>, which adds notification of text changed events.
    @Override
    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<String> handler) {
        return addHandler(handler, ValueChangeEvent.getType());
    }

    @Override
    public String getValue() {
        return getText();
    }

    @Override
    public void setValue(String value) {
        setText(value);
    }

    @Override
    public void setValue(String value, boolean fireEvents) {
        // Set the value before we fire the event, so that consumers can normalize the text in any event
        // handlers.
        String startingValue = getValue();
        setValue(value);

        if (fireEvents) {
            ValueChangeEvent.fireIfNotEqual(this, startingValue, value);
        }
    }

    // Implementation of HasText, enabling you to set the default text when used in a UIBinder.
    @Override
    public void setText(String text) {
        label.setText(text);
        textArea.setText(text);
    }

    @Override
    public String getText() {
        return label.getText();
    }
}