예제 #1
0
        /// <summary>
        /// Draws the given cells using a Graphics2D canvas and returns the buffered image
        /// that represents the cells.
        /// </summary>
        public static mxICanvas DrawCells(mxGraph graph, Object[] cells, double scale,
                                          mxRectangle clip, CanvasFactory factory)
        {
            mxICanvas canvas = null;

            if (cells == null)
            {
                cells = new Object[] { graph.Model.Root };
            }

            if (cells != null)
            {
                // Gets the current state of the view
                mxGraphView view = graph.View;
                Dictionary <Object, mxCellState> states = view.States;
                double oldScale = view.Scale;

                // Keeps the existing translation as the cells might
                // be aligned to the grid in a different way in a graph
                // that has a translation other than zero
                bool eventsEnabled = view.IsEventsEnabled;

                // Disables firing of scale events so that there is no
                // repaint or update of the original graph
                view.IsEventsEnabled = false;

                try
                {
                    // TODO: Factor-out into mxTemporaryCellStates class
                    view.States = new Dictionary <Object, mxCellState>();
                    view.Scale  = scale;

                    // Validates the vertices and edges without adding them to
                    // the model so that the original cells are not modified
                    for (int i = 0; i < cells.Length; i++)
                    {
                        view.ValidateCellState(view.ValidateCell(cells[i]));
                    }

                    if (clip == null)
                    {
                        clip = graph.GetPaintBounds(cells);
                    }

                    if (clip != null && clip.Width > 0 && clip.Height > 0)
                    {
                        Rectangle rect = clip.GetRectangle();
                        canvas = factory.CreateCanvas(rect.Width + 1,
                                                      rect.Height + 1);

                        if (canvas != null)
                        {
                            double previousScale     = canvas.Scale;
                            Point  previousTranslate = canvas.Translate;

                            try
                            {
                                canvas.Translate = new Point(-rect.X, -rect.Y);
                                canvas.Scale     = view.Scale;

                                for (int i = 0; i < cells.Length; i++)
                                {
                                    graph.DrawCell(canvas, cells[i]);
                                }
                            }
                            finally
                            {
                                canvas.Scale     = previousScale;
                                canvas.Translate = previousTranslate;
                            }
                        }
                    }
                }
                finally
                {
                    view.Scale           = oldScale;
                    view.States          = states;
                    view.IsEventsEnabled = eventsEnabled;
                }
            }

            return(canvas);
        }