com.google.gwt.view.client.HasData.java Source code

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Here is the source code for com.google.gwt.view.client.HasData.java

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/*
 * Copyright 2010 Google Inc.
 * 
 * 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.gwt.view.client;

import java.util.List;

/**
 * A view that can display a range of data.
 * 
 * @param <T> the data type of each row
 */
public interface HasData<T> extends HasRows, HasCellPreviewHandlers<T> {

    /**
     * Get the {@link SelectionModel} used by this {@link HasData}.
     * 
     * @return the {@link SelectionModel}
     * 
     * @see #setSelectionModel(SelectionModel)
     */
    SelectionModel<? super T> getSelectionModel();

    /**
     * Get the row value at the specified visible index. Index 0 corresponds to
     * the first item on the page.
     * 
     * @param indexOnPage the index on the page
     * @return the row value
     */
    T getVisibleItem(int indexOnPage);

    /**
     * Get the number of visible items being displayed. Note that this value might
     * be less than the page size if there is not enough data to fill the page.
     * 
     * @return the number of visible items on the page
     */
    int getVisibleItemCount();

    /**
     * Get an {@link Iterable} composed of all of the visible items.
     * 
     * @return an {@link Iterable} instance
     */
    Iterable<T> getVisibleItems();

    /**
     * <p>
     * Set a values associated with the rows in the visible range.
     * </p>
     * <p>
     * This method <i>does not</i> replace all rows in the display; it replaces
     * the row values starting at the specified start index through the length of
     * the the specified values. You must call {@link #setRowCount(int)} to set
     * the total number of rows in the display. You should also use
     * {@link #setRowCount(int)} to remove rows when the total number of rows
     * decreases.
     * </p>
     * 
     * @param start the start index of the data
     * @param values the values within the range
     */
    void setRowData(int start, List<? extends T> values);

    /**
     * Set the {@link SelectionModel} used by this {@link HasData}.
     * 
     * @param selectionModel the {@link SelectionModel}
     * 
     * @see #getSelectionModel()
     */
    void setSelectionModel(SelectionModel<? super T> selectionModel);

    /**
     * <p>
     * Set the visible range and clear the current visible data.
     * </p>
     * <p>
     * If the second argument <code>forceRangeChangeEvent</code> is true, a
     * {@link RangeChangeEvent} will be fired even if the range does not change.
     * If false, a {@link RangeChangeEvent} will only be fired if the range
     * changes.
     * </p>
     * 
     * @param range the new {@link Range}
     * @param forceRangeChangeEvent true to fire a {@link RangeChangeEvent} even
     *          if the {@link Range} doesn't change
     */
    void setVisibleRangeAndClearData(Range range, boolean forceRangeChangeEvent);
}