EFCNBackgroundPanel


1   package snow.utils.gui;
2   
3     /**
4      *  A panel used as background for panels.
5      *  Has some gradient and other drawing stuff on it.
6      *
7      *  Note: You have to call setOpaque(false) for all
8      *        swing objects, which you add to this panel,
9      *        otherwise you wont see the panel color gradient.
10     *
11     *  Copied from EFCN:     http://www.snowraver.org
12     */
13  
14  import javax.swing.*;
15  import javax.swing.border.*;
16  import java.awt.*;
17  import java.io.*;
18  import java.util.*;
19  import java.awt.event.*;
20  import java.beans.*;
21  
22  
23  public final class EFCNBackgroundPanel extends JPanel
24  {
25  
26    // The gradient types :
27    public static final int ApplyUpperLeftCornerHighLight = 0;
28    public static final int ApplyVerticalHighLight = 1;
29  
30    // Some predefined color keystrings :
31    public static final String   ActiveTitleBackground = "InternalFrame.activeTitleBackground";
32    public static final String   PanelBackground       = "Panel.background";
33  
34  
35    // The gradient strength :
36    public static final int LightGradientStrength  = 0;
37    public static final int MediumGradientStrength = 1;
38    public static final int StrongGradientStrength = 2;
39  
40  
41    private Color lightColor  = new Color(190,190,250);
42    private Color mediumColor = new Color(120,120,180);
43    private Color darkColor   = new Color(80,80,120);
44    float xGradient;
45  
46    private Color basisColor; // around this the gradient will be
47  
48    // gradient look : (defaults)
49    private int gradientType     = ApplyUpperLeftCornerHighLight;
50    private int gradientStrength = MediumGradientStrength;
51    private String   colorKey      = ActiveTitleBackground;
52  
53  
54    private boolean useParentBackGround = false; // when a background color has been assigned
55  
56  
57  
58  
59  
60   /**
61    *  Creates a panel where you can pass
62    *  theGradientType = ApplyUpperLeftCornerHighLight
63    *                 or ApplyVerticalHighLight
64    *
65    *  and
66    *  theGradientStrength = LightGradientStrength
67    *                     or MediumGradientStrength
68    *                     or StrongGradientStrength
69    *
70    *  and
71    *  theColorKey = null
72    *             or ActiveTitleBackground
73    *             or PanelBackground
74    *             or any valid theme colorkey.
75    *
76    */
77    public EFCNBackgroundPanel( int    theGradientType,
78                                int    theGradientStrength,
79                                String   theColorKey          )
80    {
81      this( new BorderLayout(),true,theGradientType,theGradientStrength,theColorKey );
82    }
83  
84  
85  
86  
87  
88   /**
89    *  Creates a panel where you can pass
90    *  theGradientType = ApplyUpperLeftCornerHighLight
91    *                 or ApplyVerticalHighLight
92    *
93    *  and
94    *  theGradientStrength = LightGradientStrength
95    *                     or MediumGradientStrength
96    *                     or StrongGradientStrength
97    *
98    *  and
99    *  theColorKey = null
100   *             or ActiveTitleBackground
101   *             or PanelBackground
102   *             or any valid theme colorkey.
103   *
104   */
105   public EFCNBackgroundPanel( LayoutManager layout,
106                               int    theGradientType,
107                               int    theGradientStrength,
108                               String   theColorKey    )
109   {
110     this(layout,true,theGradientType,theGradientStrength,theColorKey);
111   }
112 
113 
114 
115 
116  /**
117   *  Creates a panel where you can pass
118   *  theGradientType = ApplyUpperLeftCornerHighLight
119   *                 or ApplyVerticalHighLight
120   *
121   *  and
122   *  theGradientStrength = LightGradientStrength
123   *                     or MediumGradientStrength
124   *                     or StrongGradientStrength
125   *
126   *  and
127   *  theColorKey = null
128   *             or ActiveTitleBackground
129   *             or PanelBackground
130   *             or any valid theme colorkey.
131   *
132   */
133   public EFCNBackgroundPanel( LayoutManager layout,
134                               boolean isDoubleBuffered,
135                               int    theGradientType,
136                               int    theGradientStrength,
137                               String   theColorKey   )
138   {
139     super(layout,isDoubleBuffered);
140     this.gradientType = theGradientType;
141     this.gradientStrength = theGradientStrength;
142     this.updateSpecialUI(); // sets basisColor, startColor and endColor
143     if( colorKey != null )
144     {
145        this.colorKey = theColorKey;
146     } // else use the default
147     // scale the gradient along with the current font size :
148     float unitSize = UIManager.getFont("TextField.font").getSize2D();
149     this.xGradient = unitSize;
150 
151     // additional tasks on lookand feel changes :
152     this.addPropertyChangeListener(
153      new PropertyChangeListener()
154      {
155         public void propertyChange(PropertyChangeEvent e)
156         {
157          if( !useParentBackGround ) // only if setBackground was never called
158           {
159             String   name = e.getPropertyName();
160             if (name.equals("ancestor"))
161              {
162                SwingUtilities.invokeLater( new Runnable  ()
163                 {
164                    public void run()
165                    {
166                     updateSpecialUI();
167                     // rescale the gradient along with the current font size :
168                     float unitSize = UIManager.getFont("TextField.font").getSize2D();
169                     xGradient = unitSize;
170                    }
171                 });
172              }
173           }
174         }
175      });
176 
177   } // Constructor
178 
179 
180 
181  /**
182   *  Seta a fixed background color, and with that : turns out the
183   *  UIManager update mechanism.
184   */
185   public void setBackground( Color bgColor )
186   {
187     super.setBackground(bgColor);
188     this.useParentBackGround = true; // turns off UIManager special update
189     this.basisColor = super.getBackground();
190     this.calculateColors();
191   }
192 
193 
194 
195  /**
196   * Calculate the start and endcolor of the gradient
197   * taking the basisColor as center color :
198   */
199   private void calculateColors()
200   {
201     int colorOffset = 50; // medium gradient strength
202     if( this.gradientStrength == LightGradientStrength )
203      {
204        colorOffset = 30;
205      }
206     if( this.gradientStrength == StrongGradientStrength )
207      {
208        colorOffset = 70;
209      }
210     int rBase = this.basisColor.getRed();
211     int gBase = this.basisColor.getGreen();
212     int bBase = this.basisColor.getBlue();
213     // start color is lighter :
214     int rStart = rBase + colorOffset;
215     int gStart = gBase + colorOffset;
216     int bStart = bBase + colorOffset;
217     if(  (rStart <= 255) && (gStart <= 255) && (bStart <= 255) )
218      {
219        this.lightColor = new Color( rStart,gStart,bStart );
220      } else
221      {
222        if( rStart > 255 ) rStart = 255;
223        if( gStart > 255 ) gStart = 255;
224        if( bStart > 255 ) bStart = 255;
225        this.lightColor = new Color( rStart,gStart,bStart );
226      }
227 
228     this.mediumColor = this.basisColor;
229 
230     rStart = rBase - colorOffset;
231     gStart = gBase - colorOffset;
232     bStart = bBase - colorOffset;
233     if(  (rStart >= 0) && (gStart >= 0) && (bStart >= 0) )
234      {
235        this.darkColor = new Color( rStart,gStart,bStart );
236      } else
237      {
238        if( rStart < 0 ) rStart = 0;
239        if( gStart < 0 ) gStart = 0;
240        if( bStart < 0 ) bStart = 0;
241        this.darkColor = new Color( rStart,gStart,bStart );
242      }
243 
244   }
245 
246 
247  /**
248   *  Must be called, when the lf theme changes.
249   *  Called by the propertychange listener above.
250   */
251   public void updateSpecialUI()
252   {
253     // Derive the basisColor :
254     Color color = UIManager.getColor(this.colorKey);
255     if( color == null )
256      {
257        color = new Color(250,170,150); // give it a green color to show
258      }                                 // that the key was invalid.
259     // give a little bit more blue
260     int r = color.getRed()   - 3;
261     int g = color.getGreen() - 3;
262     int b = color.getBlue()  + 6;
263     // level out grayscale value a bit :
264     if( r+g+b > 384 )
265      {
266        r -= 10;
267        g -= 10;
268        b -= 10;
269      } else
270      {
271        r += 10;
272        g += 10;
273        b += 10;
274      }
275     // keep in range :
276     if( r < 0 ) r = 0; if( r > 255 ) r = 255;
277     if( g < 0 ) g = 0; if( g > 255 ) g = 255;
278     if( b < 0 ) b = 0; if( b > 255 ) b = 255;
279     // and set it as basis :
280     this.basisColor = new Color(r,g,b);
281     // Calculate the start and endColors from that :
282     this.calculateColors();
283   }
284 
285 
286  /**
287   *  Overwritten paint method to have a slight color gradient.
288   */
289   public void paint( Graphics g )
290   {
291     Graphics2D graphics2D = (Graphics2D)g;
292     final Paint savePaint = graphics2D.getPaint();
293     if( this.gradientType == ApplyUpperLeftCornerHighLight )
294      {
295       GradientPaint upperLeftGradientPaint =
296                     new GradientPaint( 0f,0f,
297                                        lightColor,
298                                        xGradient,xGradient*5.0f,
299                                        mediumColor );
300 
301       graphics2D.setPaint( upperLeftGradientPaint );
302       graphics2D.fill( graphics2D.getClip() );
303      }
304     else if( this.gradientType == ApplyVerticalHighLight )
305      {
306 
307       float gradientLength = xGradient;
308       if( gradientLength > this.getHeight()/2.5f )
309        {
310          gradientLength = this.getHeight()/2.5f;
311        }
312       GradientPaint upperVerticalGradientPaint =
313                     new GradientPaint( 0f,0f,
314                                        this.lightColor,
315                                        0f, gradientLength,
316                                        this.mediumColor );
317 
318       GradientPaint lowerVerticalGradientPaint =
319                     new GradientPaint( 0f,getHeight(),
320                                        this.darkColor,
321                                        0f,getHeight() - gradientLength,
322                                        this.mediumColor );
323 
324       Shape saveClip = graphics2D.getClip();
325 
326       graphics2D.setPaint( lowerVerticalGradientPaint );
327       graphics2D.fill( graphics2D.getClip() );
328 
329       Rectangle r = new Rectangle( 0,0,getWidth(),1+getHeight()/2 );
330       graphics2D.setPaint( upperVerticalGradientPaint );
331       graphics2D.fill( r );
332 
333       graphics2D.setClip(saveClip);
334      }
335     graphics2D.setPaint( savePaint );
336     super.paintChildren(graphics2D);
337   } // paint
338 
339 
340 
341 
342  /**
343   *  Overwitten, so it doesnt clear all, but
344   *  one has to call super, so children are properly rendered.
345   */
346   public void update( Graphics g )
347   {
348    //super.update(g);
349    paint(g);
350   }
351 
352 
353 
354 
355 } // EFCNBackgroundPanel
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