net.mograsim.logic.model/src/net/mograsim/logic/model/snippets/CodeSnippetSupplier.java

   1 package net.mograsim.logic.model.snippets;
   2
   3 import java.util.Collections;
   4 import java.util.HashMap;
   5 import java.util.Map;
   6
   7 public class CodeSnippetSupplier<C, S>
   8 {
   9         private final Map<String, String> standardSnippetIDClassNames = new HashMap<>();
  10         private final Map<String, String> standardSnippetIDClassNamesUnmodifiable = Collections.unmodifiableMap(standardSnippetIDClassNames);
  11         private final Map<String, SnippetDefinintion<C, ?, S>> snippetSuppliersForClassNames = new HashMap<>();
  12         private final SnippetDefinintion<C, ?, S> defaultSnippetSupplier;
  13
  14         public CodeSnippetSupplier(SnippetDefinintion<C, ?, S> defaultSnippetSupplier)
  15         {
  16                 this.defaultSnippetSupplier = defaultSnippetSupplier;
  17         }
  18
  19         public void addStandardSnippetID(String standardSnippetID, String associatedSnippetID)
  20         {
  21                 if (!associatedSnippetID.startsWith("class:"))
  22                         throw new IllegalArgumentException("Unrecognized snippet ID format: " + associatedSnippetID);
  23                 standardSnippetIDClassNames.put(standardSnippetID, associatedSnippetID);
  24         }
  25
  26         public Map<String, String> getStandardSnippetIDs()
  27         {
  28                 return standardSnippetIDClassNamesUnmodifiable;
  29         }
  30
  31         public void setSnippetSupplier(String id, SnippetDefinintion<C, ?, S> snippetSupplier)
  32         {
  33                 snippetSuppliersForClassNames.put(id, snippetSupplier);
  34         }
  35
  36         // TODO report errors
  37         public SnippetDefinintion<C, ?, S> getSnippetSupplier(String id)
  38         {
  39                 if (id != null)
  40                 {
  41                         String resolvedID = resolveID(id);
  42                         if (resolvedID != null)
  43                         {
  44                                 String snippetClassName = resolvedID.substring(6);
  45                                 tryLoadSnippetClass(snippetClassName);
  46                                 SnippetDefinintion<C, ?, S> snippetSupplier = snippetSuppliersForClassNames.get(snippetClassName);
  47                                 if (snippetSupplier != null)
  48                                         return snippetSupplier;
  49                         }
  50                         System.err.println("Couldn't load snippet " + id + "; using default");
  51                 }
  52                 if (defaultSnippetSupplier == null)
  53                         throw new IllegalArgumentException("No default snippet set");
  54                 return defaultSnippetSupplier;
  55         }
  56
  57         public String resolveID(String id)
  58         {
  59                 if (id.startsWith("class:"))
  60                         return id;
  61                 return standardSnippetIDClassNames.get(id);
  62         }
  63
  64         // static helpers
  65
  66         private static void tryLoadSnippetClass(String snippetClassName)
  67         {
  68                 tryInvokeStaticInitializer(snippetClassName, "Error getting snippet class: %s: %s\n");
  69         }
  70
  71         public static void tryInvokeStaticInitializer(String className, String errorMessageFormat)
  72         {
  73                 try
  74                 {
  75                         Class.forName(className, true, CodeSnippetSupplier.class.getClassLoader());
  76                 }
  77                 catch (ClassNotFoundException e)
  78                 {
  79                         System.err.printf(errorMessageFormat, className, "ClassNotFoundException thrown: " + e.getMessage());
  80                 }
  81         }
  82
  83 }