1 files changed, 183 insertions, 0 deletions
diff --git a/java/src/org/kelar/inputmethod/latin/utils/SpannableStringUtils.java b/java/src/org/kelar/inputmethod/latin/utils/SpannableStringUtils.java
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index 000000000..e3c6d60bf
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+++ b/java/src/org/kelar/inputmethod/latin/utils/SpannableStringUtils.java
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.kelar.inputmethod.latin.utils;
+
+import android.text.Spannable;
+import android.text.SpannableString;
+import android.text.Spanned;
+import android.text.SpannedString;
+import android.text.TextUtils;
+import android.text.style.SuggestionSpan;
+import android.text.style.URLSpan;
+
+import org.kelar.inputmethod.annotations.UsedForTesting;
+
+import java.util.ArrayList;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public final class SpannableStringUtils {
+    /**
+     * Copies the spans from the region <code>start...end</code> in
+     * <code>source</code> to the region
+     * <code>destoff...destoff+end-start</code> in <code>dest</code>.
+     * Spans in <code>source</code> that begin before <code>start</code>
+     * or end after <code>end</code> but overlap this range are trimmed
+     * as if they began at <code>start</code> or ended at <code>end</code>.
+     * Only SuggestionSpans that don't have the SPAN_PARAGRAPH span are copied.
+     *
+     * This code is almost entirely taken from {@link TextUtils#copySpansFrom}, except for the
+     * kind of span that is copied.
+     *
+     * @throws IndexOutOfBoundsException if any of the copied spans
+     * are out of range in <code>dest</code>.
+     */
+    public static void copyNonParagraphSuggestionSpansFrom(Spanned source, int start, int end,
+            Spannable dest, int destoff) {
+        Object[] spans = source.getSpans(start, end, SuggestionSpan.class);
+
+        for (int i = 0; i < spans.length; i++) {
+            int fl = source.getSpanFlags(spans[i]);
+            // We don't care about the PARAGRAPH flag in LatinIME code. However, if this flag
+            // is set, Spannable#setSpan will throw an exception unless the span is on the edge
+            // of a word. But the spans have been split into two by the getText{Before,After}Cursor
+            // methods, so after concatenation they may end in the middle of a word.
+            // Since we don't use them, we can just remove them and avoid crashing.
+            fl &= ~Spanned.SPAN_PARAGRAPH;
+
+            int st = source.getSpanStart(spans[i]);
+            int en = source.getSpanEnd(spans[i]);
+
+            if (st < start)
+                st = start;
+            if (en > end)
+                en = end;
+
+            dest.setSpan(spans[i], st - start + destoff, en - start + destoff,
+                         fl);
+        }
+    }
+
+    /**
+     * Returns a CharSequence concatenating the specified CharSequences, retaining their
+     * SuggestionSpans that don't have the PARAGRAPH flag, but not other spans.
+     *
+     * This code is almost entirely taken from {@link TextUtils#concat(CharSequence...)}, except
+     * it calls copyNonParagraphSuggestionSpansFrom instead of {@link TextUtils#copySpansFrom}.
+     */
+    public static CharSequence concatWithNonParagraphSuggestionSpansOnly(CharSequence... text) {
+        if (text.length == 0) {
+            return "";
+        }
+
+        if (text.length == 1) {
+            return text[0];
+        }
+
+        boolean spanned = false;
+        for (int i = 0; i < text.length; i++) {
+            if (text[i] instanceof Spanned) {
+                spanned = true;
+                break;
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < text.length; i++) {
+            sb.append(text[i]);
+        }
+
+        if (!spanned) {
+            return sb.toString();
+        }
+
+        SpannableString ss = new SpannableString(sb);
+        int off = 0;
+        for (int i = 0; i < text.length; i++) {
+            int len = text[i].length();
+
+            if (text[i] instanceof Spanned) {
+                copyNonParagraphSuggestionSpansFrom((Spanned) text[i], 0, len, ss, off);
+            }
+
+            off += len;
+        }
+
+        return new SpannedString(ss);
+    }
+
+    public static boolean hasUrlSpans(final CharSequence text,
+            final int startIndex, final int endIndex) {
+        if (!(text instanceof Spanned)) {
+            return false; // Not spanned, so no link
+        }
+        final Spanned spanned = (Spanned)text;
+        // getSpans(x, y) does not return spans that start on x or end on y. x-1, y+1 does the
+        // trick, and works in all cases even if startIndex <= 0 or endIndex >= text.length().
+        final URLSpan[] spans = spanned.getSpans(startIndex - 1, endIndex + 1, URLSpan.class);
+        return null != spans && spans.length > 0;
+    }
+
+    /**
+     * Splits the given {@code charSequence} with at occurrences of the given {@code regex}.
+     * <p>
+     * This is equivalent to
+     * {@code charSequence.toString().split(regex, preserveTrailingEmptySegments ? -1 : 0)}
+     * except that the spans are preserved in the result array.
+     * </p>
+     * @param charSequence the character sequence to be split.
+     * @param regex the regex pattern to be used as the separator.
+     * @param preserveTrailingEmptySegments {@code true} to preserve the trailing empty
+     * segments. Otherwise, trailing empty segments will be removed before being returned.
+     * @return the array which contains the result. All the spans in the <code>charSequence</code>
+     * is preserved.
+     */
+    @UsedForTesting
+    public static CharSequence[] split(final CharSequence charSequence, final String regex,
+            final boolean preserveTrailingEmptySegments) {
+        // A short-cut for non-spanned strings.
+        if (!(charSequence instanceof Spanned)) {
+            // -1 means that trailing empty segments will be preserved.
+            return charSequence.toString().split(regex, preserveTrailingEmptySegments ? -1 : 0);
+        }
+
+        // Hereafter, emulate String.split for CharSequence.
+        final ArrayList<CharSequence> sequences = new ArrayList<>();
+        final Matcher matcher = Pattern.compile(regex).matcher(charSequence);
+        int nextStart = 0;
+        boolean matched = false;
+        while (matcher.find()) {
+            sequences.add(charSequence.subSequence(nextStart, matcher.start()));
+            nextStart = matcher.end();
+            matched = true;
+        }
+        if (!matched) {
+            // never matched. preserveTrailingEmptySegments is ignored in this case.
+            return new CharSequence[] { charSequence };
+        }
+        sequences.add(charSequence.subSequence(nextStart, charSequence.length()));
+        if (!preserveTrailingEmptySegments) {
+            for (int i = sequences.size() - 1; i >= 0; --i) {
+                if (!TextUtils.isEmpty(sequences.get(i))) {
+                    break;
+                }
+                sequences.remove(i);
+            }
+        }
+        return sequences.toArray(new CharSequence[sequences.size()]);
+    }
+}