From e931270474d5c2cd43a506b46c315bc32a5f664f Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Thu, 8 Sep 2011 12:32:39 +0200
Subject: [PATCH] if a user types a char occurring in a lookup string of the
 currently selected lookup item, insert everything that's before that
 occurrence

---
 .../codeInsight/lookup/impl/LookupImpl.java   | 32 +++++++++----------
 .../lookup/impl/LookupTypedHandler.java       | 29 ++++++++++++++++-
 2 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
index d5149450a6bb..7c475cbb125c 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
@@ -1130,29 +1130,27 @@ public class LookupImpl extends LightweightHint implements LookupEx, Disposable
       myInitialPrefix = null;
     }
 
-    final String finalCommonPrefix = commonPrefix;
-    Runnable runnable = new Runnable() {
-      public void run() {
-        doInsertCommonPrefix(presentPrefix, finalCommonPrefix);
-      }
-    };
-    performGuardedChange(runnable);
+    replacePrefix(presentPrefix, commonPrefix);
     return true;
   }
 
-  private void doInsertCommonPrefix(String presentPrefix, String newPrefix) {
-    EditorModificationUtil.deleteSelectedText(myEditor);
-    int offset = myEditor.getCaretModel().getOffset();
-    final int start = offset - presentPrefix.length();
-    myEditor.getDocument().replaceString(start, offset, newPrefix);
+  public void replacePrefix(final String presentPrefix, final String newPrefix) {
+    performGuardedChange(new Runnable() {
+      public void run() {
+        EditorModificationUtil.deleteSelectedText(myEditor);
+        int offset = myEditor.getCaretModel().getOffset();
+        final int start = offset - presentPrefix.length();
+        myEditor.getDocument().replaceString(start, offset, newPrefix);
 
-    Map<LookupElement, PrefixMatcher> newItems = myModel.retainMatchingItems(newPrefix, this);
-    myMatchers.clear();
-    myMatchers.putAll(newItems);
+        Map<LookupElement, PrefixMatcher> newItems = myModel.retainMatchingItems(newPrefix, LookupImpl.this);
+        myMatchers.clear();
+        myMatchers.putAll(newItems);
 
-    myAdditionalPrefix = "";
+        myAdditionalPrefix = "";
 
-    myEditor.getCaretModel().moveToOffset(start + newPrefix.length());
+        myEditor.getCaretModel().moveToOffset(start + newPrefix.length());
+      }
+    });
     refreshUi();
   }
 
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupTypedHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupTypedHandler.java
index 936028d22020..2d3bfd2dabf1 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupTypedHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupTypedHandler.java
@@ -92,7 +92,11 @@ public class LookupTypedHandler extends TypedHandlerDelegate {
 
       if (result == CharFilter.Result.SELECT_ITEM_AND_FINISH_LOOKUP && lookup.isFocused()) {
         LookupElement item = lookup.getCurrentItem();
-        if (item != null){
+        if (item != null) {
+          if (completeTillTypedCharOccurrence(charTyped, lookup, item)) {
+            return Result.STOP;
+          }
+
           inside = false;
           ((CommandProcessorEx)CommandProcessor.getInstance()).enterModal();
           try {
@@ -117,6 +121,29 @@ public class LookupTypedHandler extends TypedHandlerDelegate {
     }
   }
 
+  private boolean completeTillTypedCharOccurrence(char charTyped, LookupImpl lookup, LookupElement item) {
+    PrefixMatcher matcher = lookup.itemMatcher(item);
+    final String oldPrefix = matcher.getPrefix() + lookup.getAdditionalPrefix();
+    PrefixMatcher expanded = matcher.cloneWithPrefix(oldPrefix + charTyped);
+    if (expanded.prefixMatches(item)) {
+      for (String s : item.getAllLookupStrings()) {
+        if (matcher.prefixMatches(s)) {
+          int i = -1;
+          while (true) {
+            i = s.indexOf(charTyped, i + 1);
+            if (i < 0)  break;
+            final String newPrefix = s.substring(0, i + 1);
+            if (expanded.prefixMatches(newPrefix)) {
+              lookup.replacePrefix(oldPrefix, newPrefix);
+              return true;
+            }
+          }
+        }
+      }
+    }
+    return false;
+  }
+
   public static void finishLookup(final char charTyped, @NotNull final LookupImpl lookup, final Runnable baseChange) {
     Editor editor = lookup.getEditor();
     FeatureUsageTracker.getInstance().triggerFeatureUsed(CodeCompletionFeatures.EDITING_COMPLETION_FINISH_BY_DOT_ETC);