Implementing Java camelCase breaking in SCL module editor

[simantics/platform.git] / bundles / org.simantics.scl.ui / src / org / simantics / scl / ui / editor2 / iterator / JavaWordIterator.java

diff --git a/bundles/org.simantics.scl.ui/src/org/simantics/scl/ui/editor2/iterator/JavaWordIterator.java b/bundles/org.simantics.scl.ui/src/org/simantics/scl/ui/editor2/iterator/JavaWordIterator.java
new file mode 100644 (file)
index 0000000..403cc9d
--- /dev/null
+++ b/bundles/org.simantics.scl.ui/src/org/simantics/scl/ui/editor2/iterator/JavaWordIterator.java
@@ -0,0 +1,224 @@
+package org.simantics.scl.ui.editor2.iterator;
+
+import java.text.CharacterIterator;
+
+import com.ibm.icu.text.BreakIterator;
+
+import org.eclipse.core.runtime.Assert;
+
+
+
+/**
+ * Breaks java text into word starts, also stops at line start and end. No
+ * direction dependency.
+ *
+ * @since 3.0
+ */
+public class JavaWordIterator extends BreakIterator {
+
+       /**
+        * The underlying java break iterator. It returns all breaks, including
+        * before and after every whitespace.
+        */
+       private JavaBreakIterator fIterator;
+       /** The current index for the stateful operations. */
+       private int fIndex;
+
+       /**
+        * Creates a new word iterator.
+        */
+       public JavaWordIterator() {
+               fIterator= new JavaBreakIterator();
+               first();
+       }
+
+       /*
+        * @see java.text.BreakIterator#first()
+        */
+       @Override
+       public int first() {
+               fIndex= fIterator.first();
+               return fIndex;
+       }
+
+       /*
+        * @see java.text.BreakIterator#last()
+        */
+       @Override
+       public int last() {
+               fIndex= fIterator.last();
+               return fIndex;
+       }
+
+       /*
+        * @see java.text.BreakIterator#next(int)
+        */
+       @Override
+       public int next(int n) {
+               int next= 0;
+               while (--n > 0 && next != DONE) {
+                       next= next();
+               }
+               return next;
+       }
+
+       /*
+        * @see java.text.BreakIterator#next()
+        */
+       @Override
+       public int next() {
+               fIndex= following(fIndex);
+               return fIndex;
+       }
+
+       /*
+        * @see java.text.BreakIterator#previous()
+        */
+       @Override
+       public int previous() {
+               fIndex= preceding(fIndex);
+               return fIndex;
+       }
+
+
+       /*
+        * @see java.text.BreakIterator#preceding(int)
+        */
+       @Override
+       public int preceding(int offset) {
+               int first= fIterator.preceding(offset);
+               if (isWhitespace(first, offset)) {
+                       int second= fIterator.preceding(first);
+                       if (second != DONE && !isDelimiter(second, first))
+                               return second;
+               }
+               return first;
+       }
+
+       /*
+        * @see java.text.BreakIterator#following(int)
+        */
+       @Override
+       public int following(int offset) {
+               int first= fIterator.following(offset);
+               if (eatFollowingWhitespace(offset, first)) {
+                       int second= fIterator.following(first);
+                       if (isWhitespace(first, second))
+                               return second;
+               }
+               return first;
+       }
+
+       private boolean eatFollowingWhitespace(int offset, int exclusiveEnd) {
+               if (exclusiveEnd == DONE || offset == DONE)
+                       return false;
+
+               if (isWhitespace(offset, exclusiveEnd))
+                       return false;
+               if (isDelimiter(offset, exclusiveEnd))
+                       return false;
+
+               return true;
+       }
+
+       /**
+        * Returns <code>true</code> if the given sequence into the underlying text
+        * represents a delimiter, <code>false</code> otherwise.
+        *
+        * @param offset the offset
+        * @param exclusiveEnd the end offset
+        * @return <code>true</code> if the given range is a delimiter
+        */
+       private boolean isDelimiter(int offset, int exclusiveEnd) {
+               if (exclusiveEnd == DONE || offset == DONE)
+                       return false;
+
+               Assert.isTrue(offset >= 0);
+               Assert.isTrue(exclusiveEnd <= getText().getEndIndex());
+               Assert.isTrue(exclusiveEnd > offset);
+
+               CharSequence seq= fIterator.fText;
+
+               while (offset < exclusiveEnd) {
+                       char ch= seq.charAt(offset);
+                       if (ch != '\n' && ch != '\r')
+                               return false;
+                       offset++;
+               }
+
+               return true;
+       }
+
+       /**
+        * Returns <code>true</code> if the given sequence into the underlying text
+        * represents whitespace, but not a delimiter, <code>false</code> otherwise.
+        *
+        * @param offset the offset
+        * @param exclusiveEnd the end offset
+        * @return <code>true</code> if the given range is whitespace
+        */
+       private boolean isWhitespace(int offset, int exclusiveEnd) {
+               if (exclusiveEnd == DONE || offset == DONE)
+                       return false;
+
+               Assert.isTrue(offset >= 0);
+               Assert.isTrue(exclusiveEnd <= getText().getEndIndex());
+               Assert.isTrue(exclusiveEnd > offset);
+
+               CharSequence seq= fIterator.fText;
+
+               while (offset < exclusiveEnd) {
+                       char ch= seq.charAt(offset);
+                       if (!Character.isWhitespace(ch))
+                               return false;
+                       if (ch == '\n' || ch == '\r')
+                               return false;
+                       offset++;
+               }
+
+               return true;
+       }
+
+       /*
+        * @see java.text.BreakIterator#current()
+        */
+       @Override
+       public int current() {
+               return fIndex;
+       }
+
+       /*
+        * @see java.text.BreakIterator#getText()
+        */
+       @Override
+       public CharacterIterator getText() {
+               return fIterator.getText();
+       }
+
+       /**
+        * Sets the text as <code>CharSequence</code>.
+        * @param newText the new text
+        */
+       public void setText(CharSequence newText) {
+               fIterator.setText(newText);
+               first();
+       }
+
+       /*
+        * @see java.text.BreakIterator#setText(java.text.CharacterIterator)
+        */
+       @Override
+       public void setText(CharacterIterator newText) {
+               fIterator.setText(newText);
+               first();
+       }
+
+       /*
+        * @see java.text.BreakIterator#setText(java.lang.String)
+        */
+       @Override
+       public void setText(String newText) {
+               setText((CharSequence) newText);
+       }
+
+}