Draw Dashed : Line « 2D Graphics « Java Tutorial





/*
    GNU LESSER GENERAL PUBLIC LICENSE
    Copyright (C) 2006 The Lobo Project

    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.

    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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Contact info: lobochief@users.sourceforge.net
*/

import java.awt.*;

public class GUITasks {
  public static Frame getTopFrame() {
    Frame[] frames = Frame.getFrames();
    for(int i = 0; i < frames.length; i++) {
      if(frames[i].getFocusOwner() != null) {
        return frames[i];
      }
    }
    if(frames.length > 0) {
      return frames[0];
    }
    return null;
  }
  
  public static void drawDashed(Graphics g, int x1, int y1, int x2, int y2, int dashSize, int gapSize) {
    if(x2 < x1) {
      int temp = x1;
      x1 = x2;
      x2 = temp;
    }
    if(y2 < y1) {
      int temp = y1;
      y1 = y2;
      y2 = temp;
    }
    int totalDash = dashSize + gapSize;
    if(y1 == y2) {
      int virtualStartX = (x1 / totalDash) * totalDash;
      for(int x = virtualStartX; x < x2; x += totalDash) {
        int topX = x + dashSize;
        if(topX > x2) {
          topX = x2;
        }
        int firstX = x;
        if(firstX < x1) {
          firstX = x1;
        }
        if(firstX < topX) {
          g.drawLine(firstX, y1, topX, y1);
        }
      }
    }
    else if(x1 == x2) {
      int virtualStartY = (y1 / totalDash) * totalDash;
      for(int y = virtualStartY; y < y2; y += totalDash) {
        int topY = y + dashSize;
        if(topY > y2) {
          topY = y2;
        }
        int firstY = y;
        if(firstY < y1) {
          firstY = y1;
        }
        if(firstY < topY) {
          g.drawLine(x1, firstY, x1, topY);
        }
      }     
    }
    else {
      // Not supported
      g.drawLine(x1, y1, x2, y2);
    }
  }
}










16.12.Line
16.12.1.Draw a lineDraw a line
16.12.2.draw Line from (10, 15) to (100, 115)
16.12.3.Line2D.FloatLine2D.Float
16.12.4.Draw a point: use a drawLine() method
16.12.5.A line is drawn using two points
16.12.6.Dash style line
16.12.7.Line dashes style 2
16.12.8.Lines Dashes style 3
16.12.9.Line Dash Style 4
16.12.10.Draw Dashed
16.12.11.Compares two lines are returns true if they are equal or both null.
16.12.12.Creates a region surrounding a line segment by 'widening' the line segment.