Switch from HtmlSpanner to HtmlTextView

This commit is contained in:
Dominik Schürmann
2013-09-09 13:16:54 +02:00
parent 5dc693c64c
commit 5b6880d2e3
19 changed files with 864 additions and 80 deletions

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/*
* Copyright (C) 2013 Mohammed Lakkadshaw
*
* 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.Vector;
import org.xml.sax.XMLReader;
import android.text.Editable;
import android.text.Html;
import android.text.Spannable;
import android.text.style.BulletSpan;
import android.text.style.LeadingMarginSpan;
import android.text.style.TypefaceSpan;
import android.util.Log;
public class HtmlTagHandler implements Html.TagHandler {
private int mListItemCount = 0;
private Vector<String> mListParents = new Vector<String>();
@Override
public void handleTag(final boolean opening, final String tag, Editable output, final XMLReader xmlReader) {
if (tag.equals("ul") || tag.equals("ol") || tag.equals("dd")) {
if (opening) {
mListParents.add(tag);
} else mListParents.remove(tag);
mListItemCount = 0;
} else if (tag.equals("li") && !opening) {
handleListTag(output);
} else if (tag.equalsIgnoreCase("code")) {
if (opening) {
output.setSpan(new TypefaceSpan("monospace"), output.length(), output.length(), Spannable.SPAN_MARK_MARK);
} else {
Log.d(HtmlTextView.TAG, "Code tag encountered");
Object obj = getLast(output, TypefaceSpan.class);
int where = output.getSpanStart(obj);
output.setSpan(new TypefaceSpan("monospace"), where, output.length(), 0);
}
}
}
private Object getLast(Editable text, Class kind) {
Object[] objs = text.getSpans(0, text.length(), kind);
if (objs.length == 0) {
return null;
} else {
for (int i = objs.length; i > 0; i--) {
if (text.getSpanFlags(objs[i - 1]) == Spannable.SPAN_MARK_MARK) {
return objs[i - 1];
}
}
return null;
}
}
private void handleListTag(Editable output) {
if (mListParents.lastElement().equals("ul")) {
output.append("\n");
String[] split = output.toString().split("\n");
int lastIndex = split.length - 1;
int start = output.length() - split[lastIndex].length() - 1;
output.setSpan(new BulletSpan(15 * mListParents.size()), start, output.length(), 0);
} else if (mListParents.lastElement().equals("ol")) {
mListItemCount++;
output.append("\n");
String[] split = output.toString().split("\n");
int lastIndex = split.length - 1;
int start = output.length() - split[lastIndex].length() - 1;
output.insert(start, mListItemCount + ". ");
output.setSpan(new LeadingMarginSpan.Standard(15 * mListParents.size()), start, output.length(), 0);
}
}
}

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/*
* Copyright (C) 2013 Dominik Schürmann <dominik@dominikschuermann.de>
*
* 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 android.content.Context;
import android.text.Html;
import android.text.method.LinkMovementMethod;
import android.util.AttributeSet;
import java.io.InputStream;
public class HtmlTextView extends JellyBeanSpanFixTextView {
public static final String TAG = "HtmlTextView";
public HtmlTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public HtmlTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public HtmlTextView(Context context) {
super(context);
}
/**
* http://stackoverflow.com/questions/309424/read-convert-an-inputstream-to-a-string
*
* @param is
* @return
*/
static private String convertStreamToString(java.io.InputStream is) {
java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
return s.hasNext() ? s.next() : "";
}
/**
* Loads HTML from a raw resource, i.e., a HTML file in res/raw/.
* This allows translatable resource (e.g., res/raw-de/ for german).
* The containing HTML is parsed to Android's Spannable format and then displayed.
*
* @param context
* @param id for example: R.raw.help
*/
public void setHtmlFromRawResource(Context context, int id) {
// load html from html file from /res/raw
InputStream inputStreamText = context.getResources().openRawResource(id);
setHtmlFromString(convertStreamToString(inputStreamText));
}
/**
* Parses String containing HTML to Android's Spannable format and displays it in this TextView.
*
* @param html String containing HTML, for example: "<b>Hello world!</b>"
*/
public void setHtmlFromString(String html) {
// this uses Android's Html class for basic parsing, and HtmlTagHandler
setText(Html.fromHtml(html, new UrlImageGetter(this, getContext()), new HtmlTagHandler()));
// make links work
setMovementMethod(LinkMovementMethod.getInstance());
// no flickering when clicking textview for Android < 4
// text.setTextColor(getResources().getColor(android.R.color.secondary_text_dark_nodisable));
}
}

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/*
* 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);
}
}

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/*
* Copyright (C) 2013 Antarix Tandon
*
* 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 android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.text.Html.ImageGetter;
import android.view.View;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
public class UrlImageGetter implements ImageGetter {
Context c;
View container;
/**
* Construct the URLImageParser which will execute AsyncTask and refresh the container
*
* @param t
* @param c
*/
public UrlImageGetter(View t, Context c) {
this.c = c;
this.container = t;
}
public Drawable getDrawable(String source) {
UrlDrawable urlDrawable = new UrlDrawable();
// get the actual source
ImageGetterAsyncTask asyncTask = new ImageGetterAsyncTask(urlDrawable);
asyncTask.execute(source);
// return reference to URLDrawable where I will change with actual image from
// the src tag
return urlDrawable;
}
public class ImageGetterAsyncTask extends AsyncTask<String, Void, Drawable> {
UrlDrawable urlDrawable;
public ImageGetterAsyncTask(UrlDrawable d) {
this.urlDrawable = d;
}
@Override
protected Drawable doInBackground(String... params) {
String source = params[0];
return fetchDrawable(source);
}
@Override
protected void onPostExecute(Drawable result) {
// set the correct bound according to the result from HTTP call
urlDrawable.setBounds(0, 0, 0 + result.getIntrinsicWidth(), 0 + result.getIntrinsicHeight());
// change the reference of the current drawable to the result
// from the HTTP call
urlDrawable.drawable = result;
// redraw the image by invalidating the container
UrlImageGetter.this.container.invalidate();
}
/**
* Get the Drawable from URL
*
* @param urlString
* @return
*/
public Drawable fetchDrawable(String urlString) {
try {
InputStream is = fetch(urlString);
Drawable drawable = Drawable.createFromStream(is, "src");
drawable.setBounds(0, 0, 0 + drawable.getIntrinsicWidth(), 0 + drawable.getIntrinsicHeight());
return drawable;
} catch (Exception e) {
return null;
}
}
private InputStream fetch(String urlString) throws MalformedURLException, IOException {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet request = new HttpGet(urlString);
HttpResponse response = httpClient.execute(request);
return response.getEntity().getContent();
}
}
@SuppressWarnings("deprecation")
public class UrlDrawable extends BitmapDrawable {
// the drawable that you need to set, you could set the initial drawing
// with the loading image if you need to
protected Drawable drawable;
@Override
public void draw(Canvas canvas) {
// override the draw to facilitate refresh function later
if (drawable != null) {
drawable.draw(canvas);
}
}
}
}