bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/KeyToSelectionAdapter.java

   1 package org.simantics.browsing.ui.swt;\r
   2 \r
   3 import java.util.regex.Pattern;\r
   4 \r
   5 import org.eclipse.swt.events.KeyAdapter;\r
   6 import org.eclipse.swt.events.KeyEvent;\r
   7 import org.eclipse.swt.widgets.Tree;\r
   8 import org.eclipse.swt.widgets.TreeItem;\r
   9 import org.simantics.browsing.ui.GraphExplorer;\r
  10 \r
  11 /**\r
  12  * Selects tree items based on pressed key events.<p>\r
  13  * \r
  14  * The default implementation of SWT.Tree (Windows?) uses only the the first column when matching the items.<p>\r
  15  * \r
  16  * This implementation checks all columns. Override <pre>matches(), matchesColumn()</pre> for customized behavior.<p>\r
  17  * \r
  18  * @author Marko Luukkainen <marko.luukkainen@vtt.fi>\r
  19  *\r
  20  */\r
  21 public class KeyToSelectionAdapter extends KeyAdapter {\r
  22 \r
  23         private static final int KEY_INPUT_DELAY = 500;\r
  24         \r
  25     private final GraphExplorer          explorer;\r
  26 \r
  27     private String matcher = "";\r
  28     private int prevEvent = 0;\r
  29     private int columns = 0;\r
  30         \r
  31     protected Pattern alphaNum;\r
  32     \r
  33     /**\r
  34      * @param contextProvider\r
  35      * @param explorer\r
  36      */\r
  37     public KeyToSelectionAdapter(GraphExplorer explorer) {\r
  38         assert explorer != null;\r
  39 \r
  40         this.explorer = explorer;\r
  41         this.alphaNum = Pattern.compile("\\p{Alnum}");\r
  42     }\r
  43 \r
  44     @Override\r
  45     public void keyPressed(KeyEvent e) {\r
  46         if (explorer.isDisposed())\r
  47             return;\r
  48 \r
  49          \r
  50          if (!alphaNum.matcher(Character.toString(e.character)).matches())\r
  51                  return;\r
  52          // concatenate / replace matcher.\r
  53          if ((e.time - prevEvent) > KEY_INPUT_DELAY )\r
  54                  matcher = "";\r
  55          prevEvent = e.time;\r
  56          matcher = matcher += Character.toString(e.character);\r
  57 \r
  58          TreeItem item = null;\r
  59          Tree tree = explorer.getControl();\r
  60          columns = tree.getColumnCount();\r
  61          TreeItem[] selected = tree.getSelection();\r
  62         \r
  63          item = find(tree, selected);\r
  64          \r
  65          if (item == null && matcher.length() > 1) {\r
  66                  matcher = matcher.substring(matcher.length()-1);\r
  67                  item = find(tree, selected);\r
  68          }\r
  69          \r
  70          if (item != null) {\r
  71                          tree.select(item);\r
  72                          tree.showItem(item);\r
  73                         \r
  74                  } \r
  75          // without this the default handling would take over.\r
  76          e.doit = false;\r
  77     }\r
  78     \r
  79     private TreeItem previous = null;\r
  80     private boolean foundPrev = false;\r
  81     \r
  82         private TreeItem find(Tree tree, TreeItem[] selected) {\r
  83                 TreeItem item = null;\r
  84 \r
  85                 TreeItem items[] = tree.getItems();\r
  86                 if (selected.length == 0) {\r
  87                         previous = null;\r
  88                         foundPrev = true;\r
  89                         item = findItem(items, 0);\r
  90 \r
  91                 } else {\r
  92                         previous = selected[0];\r
  93                         foundPrev = false;\r
  94                         item = findItem(items, 0);\r
  95                         if (item == null) {\r
  96                                 previous = null;\r
  97                                 foundPrev = true;\r
  98                                 item = findItem(items, 0);\r
  99                         }\r
 100                 }\r
 101                 return item;\r
 102         }\r
 103     \r
 104     private TreeItem findItem(TreeItem items[], int depth) {\r
 105         for (int i = 0; i < items.length; i++) {\r
 106                 TreeItem item = items[i];\r
 107                 if (item != previous) {\r
 108                         if (foundPrev && matches(item, depth, columns, matcher))\r
 109                                 return item;\r
 110                         \r
 111                 } else {\r
 112                         foundPrev = true;\r
 113                 }\r
 114                 TreeItem childItem = findItem(item.getItems(),depth+1); \r
 115                 if (childItem != null)\r
 116                         return childItem;\r
 117         }\r
 118         return null;\r
 119     }\r
 120     \r
 121     \r
 122     /**\r
 123      * \r
 124      * @param item\r
 125      * @param depth Depth of the item in the tree.\r
 126      * @param columns Number of columns.\r
 127      * @param string Matching string.\r
 128      * @return\r
 129      */\r
 130     protected boolean matches(TreeItem item, int depth, int columns, String matcher) {\r
 131         for (int c = 0; c < columns; c++) {     \r
 132                         if (matchesColumn(item, c, matcher)) {\r
 133                                 return true;\r
 134                         }\r
 135                 }\r
 136         return false;\r
 137     }\r
 138     \r
 139     /**\r
 140      * \r
 141      * @param item\r
 142      * @param column\r
 143      * @param matcher\r
 144      * @return\r
 145      */\r
 146     protected boolean matchesColumn(TreeItem item, int column, String matcher) {\r
 147         String text = item.getText(column);\r
 148                 if (text.toLowerCase().startsWith(matcher)) {\r
 149                         return true;\r
 150                 }\r
 151                 return false;\r
 152     }\r
 153 \r
 154 \r
 155 }\r