content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.gwt.client.ui;
  
  import org.opencms.gwt.client.ui.css.I_CmsFloatDecoratedPanelCss;
  import org.opencms.gwt.client.ui.css.I_CmsLayoutBundle;
  
  import com.google.gwt.core.client.Scheduler;
  import com.google.gwt.dom.client.Style.Float;
  import com.google.gwt.dom.client.Style.Unit;
  import com.google.gwt.dom.client.Style.Visibility;
  import com.google.gwt.user.client.ui.Composite;
  import com.google.gwt.user.client.ui.FlowPanel;
  import com.google.gwt.user.client.ui.Widget;
  
  /**
   * A widget used for laying out multiple widgets horizontally.<p>
   *
   * It contains two panels, the "primary" (or main) panel and the "float" panel,
   * to which widgets can be added. The float panel is styled so as to
   * float left of the primary panel, and the primary panel's left margin is
   * set to the width of the float panel. If the widget starts out as hidden,
   * the float panel width can not be measured, so you have to call the updateLayout
   * method  manually when the widget becomes visible.
   *
   * @since 8.0.0
   */
  public class CmsFloatDecoratedPanel extends Composite implements I_CmsTruncable {
  
      /** Css resource for this widget. */
      static final I_CmsFloatDecoratedPanelCss CSS = I_CmsLayoutBundle.INSTANCE.floatDecoratedPanelCss();
  
      /** The float panel. */
      private FlowPanel m_floatBox = new FlowPanel();
  
      /** The panel containing both the main and float panel. */
      private FlowPanel m_panel = new FlowPanel();
  
      /** The main panel. */
      private FlowPanel m_primary = new FlowPanel();
  
      /**
       * Creates a new instance of the widget.
       */
      public CmsFloatDecoratedPanel() {
  
          m_panel.setStyleName(CSS.floatDecoratedPanel());
          m_floatBox.setStyleName(CSS.floatBox());
          m_primary.setStyleName(CSS.primary());
  
          m_panel.add(m_floatBox);
          m_panel.add(m_primary);
          m_floatBox.getElement().getStyle().setFloat(Float.LEFT);
          initWidget(m_panel);
          // we only make the widget visible after the layout has been updated to prevent "flickering"
          getElement().getStyle().setVisibility(Visibility.HIDDEN);
      }
  
      /**
       * Adds a widget to the main panel.<p>
       *
       * @param widget the widget to add
       */
      public void add(Widget widget) {
  
          m_primary.add(widget);
      }
  
      /**
       * Adds a widget to the float panel.<p>
       *
       * @param widget the widget to add
       */
      public void addToFloat(Widget widget) {
  
          m_floatBox.add(widget);
          updateLayout();
      }
  
      /**
       * Adds a widget to the front of the float panel.<p>
       *
       * @param widget the widget to add
       */
      public void addToFrontOfFloat(Widget widget) {
  
          m_floatBox.insert(widget, 0);
      }
  
      /**
       * Returns the widget at the given position.<p>
       *
       * @param index the position
       *
       * @return  the widget at the given position
       */
      public Widget getWidget(int index) {
  
          return m_primary.getWidget(index);
      }
  
      /**
       * @see org.opencms.gwt.client.ui.I_CmsTruncable#truncate(java.lang.String, int)
       */
      public void truncate(String textMetricsPrefix, int widgetWidth) {
  
          int width = widgetWidth;
          width -= (!isAttached() ? 30 * m_floatBox.getWidgetCount() : getFloatBoxWidth());
          for (Widget widget : m_primary) {
              if (widget instanceof I_CmsTruncable) {
                  ((I_CmsTruncable)widget).truncate(textMetricsPrefix, width);
              }
          }
      }
  
      /**
       * Sets the left margin of the main panel to the width of the float panel.<p>
       */
      public void updateLayout() {
  
          // TODO: we should not do this kind of things...
          if (!isAttached()) {
              return;
          }
          int floatBoxWidth = getFloatBoxWidth();
          m_primary.getElement().getStyle().setMarginLeft(floatBoxWidth, Unit.PX);
          updateVerticalMargin();
      }
  
      /**
       * Automatically calls the updateLayout method after insertion into the DOM.<p>
       *
       * @see com.google.gwt.user.client.ui.Widget#onLoad()
       */
      @Override
      protected void onLoad() {
  
          /* defer until children have been (hopefully) layouted. */
          Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
  
              /**
               * @see com.google.gwt.user.client.Command#execute()
               */
              public void execute() {
  
                  updateLayout();
                  // layout update has finished, now it's OK to show the widget
                  getElement().getStyle().setVisibility(Visibility.VISIBLE);
              }
          });
      }
  
      /**
       * Returns the width of the float box.<p>
       *
       * @return a width
       */
      private int getFloatBoxWidth() {
  
          return m_floatBox.getOffsetWidth();
      }
  
      /**
       * Updates the vertical margin of the float box such that its vertical middle point coincides
       * with the vertical middle point of the primary panel.<p>
       */
      private void updateVerticalMargin() {
  
          int floatHeight = m_floatBox.getOffsetHeight();
          int primaryHeight = m_primary.getOffsetHeight();
          int verticalOffset = (primaryHeight - floatHeight) / 2;
          m_floatBox.getElement().getStyle().setMarginTop(verticalOffset, Unit.PX);
      }
  }
  