net.karlmartens.ui.viewer.CellSelectionModifier.java Source code

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Here is the source code for net.karlmartens.ui.viewer.CellSelectionModifier.java

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/**
 *   Copyright 2011 Karl Martens
 *
 *   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.
 *
 *   net.karlmartens.ui, is a library of UI widgets
 */
package net.karlmartens.ui.viewer;

import net.karlmartens.ui.widget.TableColumn;
import net.karlmartens.ui.widget.TableItem;

import org.eclipse.jface.util.Policy;
import org.eclipse.jface.viewers.CellEditor;
import org.eclipse.jface.viewers.EditingSupport;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.swt.graphics.Point;

public abstract class CellSelectionModifier {
    private final TableViewer _viewer;
    private final EditingSupportProxy _editSupport;

    protected CellSelectionModifier(TableViewer viewer) {
        _viewer = viewer;
        _editSupport = new EditingSupportProxy(viewer);
    }

    private boolean isEditable(Point cell) {
        _editSupport._base = getEditingSupport(cell);

        final TableItem item = _viewer.doGetItem(cell.y);
        if (!_editSupport.canEdit(item.getData()))
            return false;

        final ViewerCell vCell = getViewerCell(cell);
        if (_editSupport.getCellEditor(vCell.getElement()).isActivated())
            return false;

        return true;
    }

    protected final String[] getValues(Point[] cells) {
        final String[] values = new String[cells.length];
        for (int i = 0; i < values.length; i++) {
            final String value = getValue(cells[i]);
            values[i] = value;
        }
        return values;
    }

    protected final void setValues(Point[] cells, String[] values) {
        for (int i = 0; i < cells.length; i++) {
            setValue(cells[i], values[i]);
        }
    }

    private TableViewerColumn getViewerColumn(int index) {
        final TableColumn column = (TableColumn) _viewer.doGetColumn(index);
        return (TableViewerColumn) column.getData(Policy.JFACE + ".columnViewer");
    }

    private ViewerCell getViewerCell(Point pt) {
        final TableItem item = _viewer.doGetItem(pt.y);
        final TableViewerRow row = _viewer.getViewerRowFromItem(item);
        return row.getCell(pt.x);
    }

    private EditingSupport getEditingSupport(Point pt) {
        final EditingSupport editing = getViewerColumn(pt.x).doGetEditingSupport();
        if (editing != null)
            return editing;

        return new ReadonlyEditSupport(pt);
    }

    private String getValue(Point pt) {
        final ViewerCell cell = getViewerCell(pt);
        if (cell == null)
            return null;

        _editSupport._base = getEditingSupport(pt);
        final Object o = _editSupport.getValue(cell.getElement());
        return o.toString();
    }

    private void setValue(Point pt, String value) {
        if (!isEditable(pt))
            return;

        final ViewerCell cell = getViewerCell(pt);
        if (cell == null)
            return;

        _editSupport._base = getEditingSupport(pt);
        _editSupport.setValue(cell.getElement(), value);

    }

    private class ReadonlyEditSupport extends EditingSupport {

        private final Point _pt;

        public ReadonlyEditSupport(Point pt) {
            super(_viewer);
            _pt = pt;
        }

        @Override
        protected CellEditor getCellEditor(Object element) {
            return null;
        }

        @Override
        protected boolean canEdit(Object element) {
            return false;
        }

        @Override
        protected Object getValue(Object element) {
            final ViewerCell vCell = getViewerCell(_pt);
            return vCell.getText();
        }

        @Override
        protected void setValue(Object element, Object value) {
            // Do nothing
        }

    }
}