NodeResizeHandleProvider.java

/****************************************************************************
 **
 ** This demo file is part of yFiles for JavaFX 3.6.
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 ** Copyright (c) 2000-2023 by yWorks GmbH, Vor dem Kreuzberg 28,
 ** 72070 Tuebingen, Germany. All rights reserved.
 **
 ** yFiles demo files exhibit yFiles for JavaFX functionalities. Any redistribution
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 ** modification, is not permitted.
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 ** demo is shipped with are allowed to use the demo source code as basis
 ** for their own yFiles for JavaFX powered applications. Use of such programs is
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 ** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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package viewer.ganttchart;

import com.yworks.yfiles.geometry.PointD;
import com.yworks.yfiles.graph.INode;
import com.yworks.yfiles.view.input.ConstrainedHandle;
import com.yworks.yfiles.view.input.HandlePositions;
import com.yworks.yfiles.view.input.HandleTypes;
import com.yworks.yfiles.view.input.IHandle;
import com.yworks.yfiles.view.input.IInputModeContext;
import com.yworks.yfiles.view.input.IReshapeHandleProvider;
import javafx.scene.Cursor;


/**
 * Provides resize handles for adjusting the main activity time frame when
 * resizing an activity node.
 */
public class NodeResizeHandleProvider implements IReshapeHandleProvider {
  /**
   * The activity node that will be resized.
   */
  private final INode node;
  private final IReshapeHandleProvider wrappedProvider;

  /**
   * Initializes a new {@code NodeResizeHandleProvider} instance for the
   * given node and given original reshape handle provider.
   */
  public NodeResizeHandleProvider( INode node, IReshapeHandleProvider wrappedProvider ) {
    this.node = node;
    this.wrappedProvider = wrappedProvider;
  }

  /**
   * Returns {@link HandlePositions#HORIZONTAL}.
   */
  @Override
  public HandlePositions getAvailableHandles( IInputModeContext context ) {
    return HandlePositions.HORIZONTAL;
  }

  /**
   * Returns an invisible resize handle for adjusting the main activity time
   * frame when resizing an activity node.
   */
  @Override
  public IHandle getHandle( IInputModeContext context, HandlePositions position ) {
    return new NodeResizeHandle(
      node,
      wrappedProvider.getHandle(context, position),
      HandlePositions.WEST == position);
  }

  /**
   * Returns the original reshape handle provider wrapped in this provider.
   */
  IReshapeHandleProvider getWrapped() {
    return wrappedProvider;
  }



  /**
   * Adjusts the main activity time frame of an activity node.
   */
  public static class NodeResizeHandle extends ConstrainedHandle {
    private final INode node;
    private final boolean start;

    private double limit;

    NodeResizeHandle( INode node, IHandle wrappedHandle, boolean start ) {
      super(wrappedHandle);
      this.node = node;
      this.start = start;
    }

    /**
     * Determines if the start or end date of an activity is changed.
     */
    public boolean isStart() {
      return start;
    }

    /**
     * Returns {@link Cursor#MOVE}.
     */
    @Override
    public Cursor getCursor() {
      return Cursor.MOVE;
    }

    /**
     * Returns {@link HandleTypes#INVISIBLE}.
     */
    @Override
    public HandleTypes getType() {
      return HandleTypes.INVISIBLE;
    }

    /**
     * Restricts the resize operation to the associated node's width and
     * limits shrinking the node's width below the width required for the
     * node's lead and follow-up time.
     */
    @Override
    protected PointD constrainNewLocation(
      IInputModeContext context, PointD originalLocation, PointD newLocation
    ) {
      double x = isStart()
        ? Math.min(newLocation.x, limit)
        : Math.max(newLocation.x, limit);
      return new PointD(x, originalLocation.y);
    }

    /**
     * Determines the limit for shrinking the associated node when a resize
     * gesture starts.  
     */
    @Override
    protected void onInitialized( IInputModeContext context, PointD originalLocation ) {
      Activity activity = (Activity) node.getTag();
      double time = activity.leadTimeWidth() + activity.followUpTimeWidth();
      limit = isStart()
        ? node.getLayout().getMaxX() - time
        : node.getLayout().getX() + time;
    }
  }
}