jp.sourceforge.moreemacs/src/jp/sourceforge/moreemacs/handlers/CommandHandler.java

   1 package jp.sourceforge.moreemacs.handlers;\r
   2 \r
   3 import java.util.regex.Pattern;\r
   4 \r
   5 import jp.sourceforge.moreemacs.MoreEmacs;\r
   6 \r
   7 import org.eclipse.core.commands.AbstractHandler;\r
   8 import org.eclipse.core.commands.Command;\r
   9 import org.eclipse.core.commands.ExecutionEvent;\r
  10 import org.eclipse.core.commands.ExecutionException;\r
  11 import org.eclipse.ui.IWorkbenchWindow;\r
  12 import org.eclipse.ui.handlers.HandlerUtil;\r
  13 \r
  14 public final class CommandHandler extends AbstractHandler {\r
  15 \r
  16     @Override\r
  17     public Object execute(ExecutionEvent event) throws ExecutionException {\r
  18         IWorkbenchWindow window = HandlerUtil.getActiveWorkbenchWindow(event);\r
  19 \r
  20         Execution exe = newExecution(event);\r
  21         if(!exe.init(window)) {\r
  22             return null;\r
  23         }\r
  24         try {\r
  25             exe.execute();\r
  26         } catch (Exception e) {\r
  27             throw new ExecutionException(e.getMessage(), e);\r
  28         }\r
  29 \r
  30         return null;\r
  31     }\r
  32     \r
  33     private Execution newExecution(ExecutionEvent event) throws ExecutionException {\r
  34         try {\r
  35             String className = getExecutionClassName(event);\r
  36             Class<?> clazz = Class.forName(className);\r
  37             Object obj = clazz.newInstance();\r
  38             if(!(obj instanceof Execution)) {\r
  39                 throw new ExecutionException("the class "+clazz.getName()+\r
  40                         " does not implements Execution.");\r
  41             }\r
  42             return (Execution)obj;\r
  43         } catch (ClassNotFoundException e) {\r
  44             throw new ExecutionException(e.getMessage(), e);\r
  45         } catch (InstantiationException e) {\r
  46             throw new ExecutionException(e.getMessage(), e);\r
  47         } catch (IllegalAccessException e) {\r
  48             throw new ExecutionException(e.getMessage(), e);\r
  49         }\r
  50         \r
  51     }\r
  52     \r
  53     // naming strategy will be separated to another class.\r
  54     private static final String COMMAND_PREFIX_QUOTED = Pattern.quote(\r
  55             MoreEmacs.class.getPackage().getName());\r
  56     private static final String HANDLER_PREFIX = CommandHandler.class.getPackage().getName();\r
  57     private static final String HANDLER_SUFFIX = "Execution";\r
  58     private static String getExecutionClassName(ExecutionEvent event) {\r
  59         Command command = event.getCommand();\r
  60         String className = command.getId()\r
  61         .replaceFirst(COMMAND_PREFIX_QUOTED, HANDLER_PREFIX)\r
  62         +HANDLER_SUFFIX;\r
  63         \r
  64         \r
  65         return className;\r
  66     }\r
  67 \r
  68 }\r