Switch from HtmlSpanner to HtmlTextView

1 files changed, 212 insertions, 0 deletions

diff --git a/libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java b/libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java
new file mode 100644
index 000000000..94bf45849
--- /dev/null
+++ b/libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2013 Dominik Schürmann <dominik@dominikschuermann.de>
+ * Copyright (C) 2012 Pierre-Yves Ricau <py.ricau@gmail.com>
+ *
+ * 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.sufficientlysecure.htmltextview;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import android.content.Context;
+import android.text.SpannableStringBuilder;
+import android.text.Spanned;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.widget.TextView;
+
+/**
+ * <p>
+ * A {@link android.widget.TextView} that insert spaces around its text spans where needed to prevent
+ * {@link IndexOutOfBoundsException} in {@link #onMeasure(int, int)} on Jelly Bean.
+ * <p>
+ * When {@link #onMeasure(int, int)} throws an exception, we try to fix the text by adding spaces
+ * around spans, until it works again. We then try removing some of the added spans, to minimize the
+ * insertions.
+ * <p>
+ * The fix is time consuming (a few ms, it depends on the size of your text), but it should only
+ * happen once per text change.
+ * <p>
+ * See http://code.google.com/p/android/issues/detail?id=35466
+ * 
+ */
+public class JellyBeanSpanFixTextView extends TextView {
+
+    private static class FixingResult {
+        public final boolean fixed;
+        public final List<Object> spansWithSpacesBefore;
+        public final List<Object> spansWithSpacesAfter;
+
+        public static FixingResult fixed(List<Object> spansWithSpacesBefore,
+                List<Object> spansWithSpacesAfter) {
+            return new FixingResult(true, spansWithSpacesBefore, spansWithSpacesAfter);
+        }
+
+        public static FixingResult notFixed() {
+            return new FixingResult(false, null, null);
+        }
+
+        private FixingResult(boolean fixed, List<Object> spansWithSpacesBefore,
+                List<Object> spansWithSpacesAfter) {
+            this.fixed = fixed;
+            this.spansWithSpacesBefore = spansWithSpacesBefore;
+            this.spansWithSpacesAfter = spansWithSpacesAfter;
+        }
+    }
+
+    public JellyBeanSpanFixTextView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+    }
+
+    public JellyBeanSpanFixTextView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public JellyBeanSpanFixTextView(Context context) {
+        super(context);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        try {
+            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        } catch (IndexOutOfBoundsException e) {
+            fixOnMeasure(widthMeasureSpec, heightMeasureSpec);
+        }
+    }
+
+    /**
+     * If possible, fixes the Spanned text by adding spaces around spans when needed.
+     */
+    private void fixOnMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        CharSequence text = getText();
+        if (text instanceof Spanned) {
+            SpannableStringBuilder builder = new SpannableStringBuilder(text);
+            fixSpannedWithSpaces(builder, widthMeasureSpec, heightMeasureSpec);
+        } else {
+            if (BuildConfig.DEBUG) {
+                Log.d(HtmlTextView.TAG, "The text isn't a Spanned");
+            }
+            fallbackToString(widthMeasureSpec, heightMeasureSpec);
+        }
+    }
+
+    /**
+     * Add spaces around spans until the text is fixed, and then removes the unneeded spaces
+     */
+    private void fixSpannedWithSpaces(SpannableStringBuilder builder, int widthMeasureSpec,
+            int heightMeasureSpec) {
+        long startFix = System.currentTimeMillis();
+
+        FixingResult result = addSpacesAroundSpansUntilFixed(builder, widthMeasureSpec,
+                heightMeasureSpec);
+
+        if (result.fixed) {
+            removeUnneededSpaces(widthMeasureSpec, heightMeasureSpec, builder, result);
+        } else {
+            fallbackToString(widthMeasureSpec, heightMeasureSpec);
+        }
+
+        if (BuildConfig.DEBUG) {
+            long fixDuration = System.currentTimeMillis() - startFix;
+            Log.d(HtmlTextView.TAG, "fixSpannedWithSpaces() duration in ms: " + fixDuration);
+        }
+    }
+
+    private FixingResult addSpacesAroundSpansUntilFixed(SpannableStringBuilder builder,
+            int widthMeasureSpec, int heightMeasureSpec) {
+
+        Object[] spans = builder.getSpans(0, builder.length(), Object.class);
+        List<Object> spansWithSpacesBefore = new ArrayList<Object>(spans.length);
+        List<Object> spansWithSpacesAfter = new ArrayList<Object>(spans.length);
+
+        for (Object span : spans) {
+            int spanStart = builder.getSpanStart(span);
+            if (isNotSpace(builder, spanStart - 1)) {
+                builder.insert(spanStart, " ");
+                spansWithSpacesBefore.add(span);
+            }
+
+            int spanEnd = builder.getSpanEnd(span);
+            if (isNotSpace(builder, spanEnd)) {
+                builder.insert(spanEnd, " ");
+                spansWithSpacesAfter.add(span);
+            }
+
+            try {
+                setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec);
+                return FixingResult.fixed(spansWithSpacesBefore, spansWithSpacesAfter);
+            } catch (IndexOutOfBoundsException notFixed) {
+            }
+        }
+        if (BuildConfig.DEBUG) {
+            Log.d(HtmlTextView.TAG, "Could not fix the Spanned by adding spaces around spans");
+        }
+        return FixingResult.notFixed();
+    }
+
+    private boolean isNotSpace(CharSequence text, int where) {
+        if (where < 0)
+            return true;
+        return text.charAt(where) != ' ';
+    }
+
+    private void setTextAndMeasure(CharSequence text, int widthMeasureSpec, int heightMeasureSpec) {
+        setText(text);
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+    }
+
+    private void removeUnneededSpaces(int widthMeasureSpec, int heightMeasureSpec,
+            SpannableStringBuilder builder, FixingResult result) {
+
+        for (Object span : result.spansWithSpacesAfter) {
+            int spanEnd = builder.getSpanEnd(span);
+            builder.delete(spanEnd, spanEnd + 1);
+            try {
+                setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec);
+            } catch (IndexOutOfBoundsException ignored) {
+                builder.insert(spanEnd, " ");
+            }
+        }
+
+        boolean needReset = true;
+        for (Object span : result.spansWithSpacesBefore) {
+            int spanStart = builder.getSpanStart(span);
+            builder.delete(spanStart - 1, spanStart);
+            try {
+                setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec);
+                needReset = false;
+            } catch (IndexOutOfBoundsException ignored) {
+                needReset = true;
+                int newSpanStart = spanStart - 1;
+                builder.insert(newSpanStart, " ");
+            }
+        }
+
+        if (needReset) {
+            setText(builder);
+            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        }
+    }
+
+    private void fallbackToString(int widthMeasureSpec, int heightMeasureSpec) {
+        if (BuildConfig.DEBUG) {
+            Log.d(HtmlTextView.TAG, "Fallback to unspanned text");
+        }
+        String fallbackText = getText().toString();
+        setTextAndMeasure(fallbackText, widthMeasureSpec, heightMeasureSpec);
+    }
+
+}
\ No newline at end of file