1    package face; 
2     
3    import java.awt.*; 
4    import java.awt.event.*; 
5     
6    /** 
7     * JPG/PPM file viewer. 
8     * 
9     * Uses ImageCanvas to displayed the custom xxxFile implementations. 
10    * 
11    */ 
12   class ImageFileViewer extends Frame implements WindowListener, ActionListener, MouseListener { 
13    
14       // control buttons 
15    
16       Button ExitButton; 
17       ImageCanvas canvas; 
18    
19       public ImageFileViewer() { 
20    
21           // constructor--initialize frame 
22    
23           super("PPM/JPG File Viewer (Click on canvas to load image)"); 
24           setup(); 
25       } 
26    
27       // initialize frame contents (buttons, etc.) 
28    
29       public void setup() { 
30    
31           Panel CanvasPanel;   // panel for drawing canvas 
32           Panel ButtonPanel;   // main button panel 
33    
34           setSize(500, 400); 
35    
36           setLayout(new BorderLayout()); 
37    
38           this.setBackground(Color.gray); 
39           this.setForeground(Color.black); 
40    
41           // initialize buttons, make frame responsible for actions 
42    
43           ExitButton = new Button("Exit"); 
44           ExitButton.addActionListener(this); 
45    
46           // initialize canvas 
47    
48           canvas = new ImageCanvas(); 
49           canvas.addMouseListener(this); 
50           canvas.setSize(400, 300); 
51           canvas.setBackground(Color.black); 
52           canvas.setForeground(Color.white); 
53    
54           ButtonPanel = new Panel(); 
55    
56           // buttons will be centered 
57    
58           ButtonPanel.setLayout(new FlowLayout(FlowLayout.CENTER)); 
59    
60           // add buttons to button panel 
61    
62           ButtonPanel.add(ExitButton); 
63    
64           // add canvas to canvas panel centered 
65    
66           CanvasPanel = new Panel(); 
67           CanvasPanel.setLayout(new FlowLayout(FlowLayout.CENTER)); 
68           CanvasPanel.add(canvas); 
69    
70           // put main panels into the frame 
71    
72           add("North", new Label("")); 
73           add("South", ButtonPanel); 
74           add("Center", CanvasPanel); 
75    
76           // frame is hidden until you show it 
77    
78           setVisible(true); 
79    
80           // care about window events 
81    
82           addWindowListener(this); 
83       } 
84    
85       // under the new event handling model, you have to "implement" all 
86       // of these window operations if you're interested in any of them. 
87       // We only care about window close events. 
88    
89       public void windowDeiconified(WindowEvent event) { 
90       } 
91    
92       public void windowIconified(WindowEvent event) { 
93       } 
94    
95       public void windowActivated(WindowEvent event) { 
96       } 
97    
98       public void windowDeactivated(WindowEvent event) { 
99       } 
100   
101      public void windowOpened(WindowEvent event) { 
102      } 
103   
104      public void windowClosed(WindowEvent event) { 
105      } 
106   
107      public void windowClosing(WindowEvent event) { 
108   
109          // handle user closing frame 
110   
111          setVisible(false); // hide frame first... 
112          dispose();         // release resources and destroy frame 
113          System.exit(0);    // exit program 
114   
115      } 
116   
117      public void mouseDragged(MouseEvent event) { 
118   
119      } 
120   
121   
122      public void mousePressed(MouseEvent event) { 
123   
124          // show file dialog for loading PPM when the user clicks... 
125   
126          FileDialog f = new FileDialog(this, "Open a JPG/PPM image file", 
127                  FileDialog.LOAD); 
128          f.setFile("*.*"); 
129          f.show(); 
130          if (f.getFile() == null) { 
131              System.out.println("Image open cancelled."); 
132          } else { 
133              try { 
134                  ImageFileFormat file = null; 
135                  String temp = (f.getDirectory() + f.getFile()).toLowerCase(); 
136   
137                  temp = temp.substring(temp.lastIndexOf('.') + 1, temp.length()); 
138                  if (temp.equals("jpg") || temp.equals("jpeg")) 
139                      file = new JPGFile(f.getDirectory() + f.getFile()); 
140                  else if (temp.equals("ppm") || temp.equals("pnm")) 
141                      file = new PPMFile(f.getDirectory() + f.getFile()); 
142   
143                  setImage(file.getBytes(), file.getWidth(), file.getHeight()); 
144              } catch (Exception e) { 
145                  e.printStackTrace(); 
146              } 
147          } 
148   
149   
150      } 
151   
152      public void setImage(byte[] b, int w, int h) { 
153          canvas.readImage(b, w, h); 
154      } 
155   
156      public void setImage(int[] b, int w, int h) { 
157          canvas.readImage(b, w, h); 
158      } 
159   
160      public void setImage(double[] b, int w, int h) { 
161          canvas.readImage(b, w, h); 
162      } 
163   
164      public void mouseReleased(MouseEvent event) { 
165      } 
166   
167      public void mouseMoved(MouseEvent event) { 
168      } 
169   
170      public void mouseEntered(MouseEvent event) { 
171      } 
172   
173      public void mouseExited(MouseEvent event) { 
174      } 
175   
176      public void mouseClicked(MouseEvent event) { 
177      } 
178   
179      public void actionPerformed(ActionEvent event) { 
180   
181          // handle pushbutton events--first get source of event 
182   
183          Object source = event.getSource(); 
184   
185          if (source == ExitButton) { 
186              setVisible(false); // hide frame first... 
187              dispose();         // release resources and destroy frame 
188              System.exit(0);    // exit program 
189          } 
190      } 
191   
192   
193  }