Transfer SmartLengthInputFilter license to Tusky (#1384)

* Transfer SmartLengthInputFilter in-header license

Transfer license for file "SmartLengthInputFilter.java" from me (Diego Rossi) to Tusky and therefore also change it from the original Apache 2.0 to currently GPLv3. This was a mistake that has been sitting around for way too long.

* Rewrite SmartLengthInputFilter from Java to Kotlin

This has been done by hand, without the custom copy-paste tool.

* Fix bad references in Java files using SmartLengthInputFilter features

* Shorten code in Java classes referencing SmartLengthInputFilter instance

* Refactor SmartLengthInputFilter from class to singleton Kotlin object

* Move hasBadRatio to become a toplevel function

* Patch up all the files affected by SmartLengthInputFilter changes

* Length in SmartLengthInputFilter is const 500, simplify code accordingly

* More meaningful name for toplevel function for checking trimming ability

* Add missing license header
This commit is contained in:
HellPie 2019-07-19 20:47:30 +02:00 committed by Konrad Pozniak
parent 3b1288e99c
commit 87285ae5bf
7 changed files with 118 additions and 167 deletions

View File

@ -22,7 +22,7 @@ import androidx.room.Entity
import androidx.room.TypeConverters
import com.keylesspalace.tusky.db.Converters
import com.keylesspalace.tusky.entity.*
import com.keylesspalace.tusky.util.SmartLengthInputFilter
import com.keylesspalace.tusky.util.shouldTrimStatus
import java.util.*
@Entity(primaryKeys = ["id","accountId"])
@ -176,7 +176,7 @@ fun Status.toEntity() =
spoilerText, attachments, mentions,
false,
false,
!SmartLengthInputFilter.hasBadRatio(content, SmartLengthInputFilter.LENGTH_DEFAULT),
!shouldTrimStatus(content),
true,
poll
)

View File

@ -48,7 +48,7 @@ import com.keylesspalace.tusky.interfaces.StatusActionListener;
import com.keylesspalace.tusky.network.MastodonApi;
import com.keylesspalace.tusky.util.ListStatusAccessibilityDelegate;
import com.keylesspalace.tusky.util.PairedList;
import com.keylesspalace.tusky.util.SmartLengthInputFilter;
import com.keylesspalace.tusky.util.SmartLengthInputFilterKt;
import com.keylesspalace.tusky.util.ThemeUtils;
import com.keylesspalace.tusky.util.ViewDataUtils;
import com.keylesspalace.tusky.view.ConversationLineItemDecoration;
@ -360,10 +360,7 @@ public final class ViewThreadFragment extends SFragment implements
}
StatusViewData.Concrete updatedStatus = new StatusViewData.Builder(status)
.setCollapsible(!SmartLengthInputFilter.hasBadRatio(
status.getContent(),
SmartLengthInputFilter.LENGTH_DEFAULT
))
.setCollapsible(!SmartLengthInputFilterKt.shouldTrimStatus(status.getContent()))
.setCollapsed(isCollapsed)
.createStatusViewData();
statuses.setPairedItem(position, updatedStatus);

View File

@ -1,154 +0,0 @@
/*
* Copyright 2018 Diego Rossi (@_HellPie)
*
* 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 com.keylesspalace.tusky.util;
import android.text.InputFilter;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
/**
* A customized version of {@link android.text.InputFilter.LengthFilter} which allows smarter
* constraints and adds better visuals such as:
* <ul>
* <li>Ellipsis at the end of the constrained text to show continuation.</li>
* <li>Trimming of invisible characters (new lines, spaces, etc.) from the constrained text.</li>
* <li>Constraints end at the end of the last "word", before a whitespace.</li>
* <li>Expansion of the limit by up to 10 characters to facilitate the previous constraint.</li>
* <li>Constraints are not applied if the percentage of hidden content is too small.</li>
* </ul>
*
* Some of these features are configurable through at instancing time.
*/
public class SmartLengthInputFilter implements InputFilter {
/**
* Defines how many characters to extend beyond the limit to cut at the end of the word on the
* boundary of it rather than cutting at the word preceding that one.
*/
private static final int RUNWAY = 10;
/**
* Default for maximum status length on Mastodon and default collapsing length on Pleroma.
*/
public static final int LENGTH_DEFAULT = 500;
/**
* Stores a reusable singleton instance of a {@link SmartLengthInputFilter} already configured
* to the default maximum length of {@value #LENGTH_DEFAULT}.
*/
public static final SmartLengthInputFilter INSTANCE = new SmartLengthInputFilter(LENGTH_DEFAULT);
private final int max;
private final boolean allowRunway;
private final boolean skipIfBadRatio;
/**
* Creates a new {@link SmartLengthInputFilter} instance with a predefined maximum length and
* all the smart constraint features this class supports.
*
* @param max The maximum length before trimming. May change based on other constraints.
*/
public SmartLengthInputFilter(int max) {
this(max, true, true);
}
/**
* Fully configures a new {@link SmartLengthInputFilter} to fine tune the state of the supported
* smart constraints this class supports.
*
* @param max The maximum length before trimming.
* @param allowRunway Whether to extend {@param max} by an extra 10 characters
* and trim precisely at the end of the closest word.
* @param skipIfBadRatio Whether to skip trimming entirely if the trimmed content
* will be less than 25% of the shown content.
*/
public SmartLengthInputFilter(int max, boolean allowRunway, boolean skipIfBadRatio) {
this.max = max;
this.allowRunway = allowRunway;
this.skipIfBadRatio = skipIfBadRatio;
}
/**
* Calculates if it's worth trimming the message at a specific limit or if the content that will
* be hidden will not be enough to justify the operation.
*
* @param message The message to trim.
* @param limit The maximum length after trimming.
* @return Whether the message should be trimmed or not.
*/
public static boolean hasBadRatio(Spanned message, int limit) {
return (double) limit / message.length() > 0.75;
}
/** {@inheritDoc} */
@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
// Code originally imported from InputFilter.LengthFilter but heavily customized.
// https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/text/InputFilter.java#175
int sourceLength = source.length();
int keep = max - (dest.length() - (dend - dstart));
if (keep <= 0) return "";
if (keep >= end - start) return null; // keep original
keep += start;
// Enable skipping trimming if the ratio is not good enough
if (skipIfBadRatio && (double)keep / sourceLength > 0.75)
return null;
// Enable trimming at the end of the closest word if possible
if (allowRunway && Character.isLetterOrDigit(source.charAt(keep))) {
int boundary;
// Android N+ offer a clone of the ICU APIs in Java for better internationalization and
// unicode support. Using the ICU version of BreakIterator grants better support for
// those without having to add the ICU4J library at a minimum Api trade-off.
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
android.icu.text.BreakIterator iterator = android.icu.text.BreakIterator.getWordInstance();
iterator.setText(source.toString());
boundary = iterator.following(keep);
if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep);
} else {
java.text.BreakIterator iterator = java.text.BreakIterator.getWordInstance();
iterator.setText(source.toString());
boundary = iterator.following(keep);
if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep);
}
keep = boundary;
} else {
// If no runway is allowed simply remove whitespaces if present
while (Character.isWhitespace(source.charAt(keep - 1))) {
--keep;
if (keep == start) return "";
}
}
if (Character.isHighSurrogate(source.charAt(keep - 1))) {
--keep;
if (keep == start) return "";
}
if (source instanceof Spanned) {
return new SpannableStringBuilder(source, start, keep).append("");
} else {
return source.subSequence(start, keep) + "";
}
}
}

View File

@ -0,0 +1,111 @@
/* Copyright 2019 Tusky contributors
*
* This file is a part of Tusky.
*
* This program is free software; you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation; either version 3 of the
* License, or (at your option) any later version.
*
* Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details.
*
* You should have received a copy of the GNU General Public License along with Tusky; if not,
* see <http://www.gnu.org/licenses>. */
package com.keylesspalace.tusky.util
import android.text.InputFilter
import android.text.SpannableStringBuilder
import android.text.Spanned
/**
* Defines how many characters to extend beyond the limit to cut at the end of the word on the
* boundary of it rather than cutting at the word preceding that one.
*/
private const val RUNWAY = 10
/**
* Default for maximum status length on Mastodon and default collapsing length on Pleroma.
*/
private const val LENGTH_DEFAULT = 500
/**
* Calculates if it's worth trimming the message at a specific limit or if the content that will
* be hidden will not be enough to justify the operation.
*
* @param message The message to trim.
* @return Whether the message should be trimmed or not.
*/
fun shouldTrimStatus(message: Spanned): Boolean {
return LENGTH_DEFAULT / message.length > 0.75
}
/**
* A customized version of {@link android.text.InputFilter.LengthFilter} which allows smarter
* constraints and adds better visuals such as:
* <ul>
* <li>Ellipsis at the end of the constrained text to show continuation.</li>
* <li>Trimming of invisible characters (new lines, spaces, etc.) from the constrained text.</li>
* <li>Constraints end at the end of the last "word", before a whitespace.</li>
* <li>Expansion of the limit by up to 10 characters to facilitate the previous constraint.</li>
* <li>Constraints are not applied if the percentage of hidden content is too small.</li>
* </ul>
*/
object SmartLengthInputFilter : InputFilter {
/** {@inheritDoc} */
override fun filter(source: CharSequence, start: Int, end: Int, dest: Spanned, dstart: Int, dend: Int): CharSequence? {
// Code originally imported from InputFilter.LengthFilter but heavily customized and converted to Kotlin.
// https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/text/InputFilter.java#175
val sourceLength = source.length
var keep = LENGTH_DEFAULT - dest.length - dend - dstart
if (keep <= 0) return ""
if (keep >= end - start) return null // Keep original
keep += start
// Skip trimming if the ratio doesn't warrant it
if (keep.toDouble() / sourceLength > 0.75) return null
// Enable trimming at the end of the closest word if possible
if (source[keep].isLetterOrDigit()) {
var boundary: Int
// Android N+ offer a clone of the ICU APIs in Java for better internationalization and
// unicode support. Using the ICU version of BreakIterator grants better support for
// those without having to add the ICU4J library at a minimum Api trade-off.
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
val iterator = android.icu.text.BreakIterator.getWordInstance()
iterator.setText(source.toString())
boundary = iterator.following(keep)
if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep)
} else {
val iterator = java.text.BreakIterator.getWordInstance()
iterator.setText(source.toString())
boundary = iterator.following(keep)
if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep)
}
keep = boundary
} else {
// If no runway is allowed simply remove whitespaces if present
while(source[keep - 1].isWhitespace()) {
--keep
if (keep == start) return ""
}
}
if (source[keep - 1].isHighSurrogate()) {
--keep
if (keep == start) return ""
}
return if (source is Spanned) {
SpannableStringBuilder(source, start, keep).append("")
} else {
"${source.subSequence(start, keep)}"
}
}
}

View File

@ -18,6 +18,6 @@ package com.keylesspalace.tusky.util
import com.keylesspalace.tusky.entity.Status
fun Status.isCollapsible(): Boolean {
return !SmartLengthInputFilter.hasBadRatio(content, SmartLengthInputFilter.LENGTH_DEFAULT)
return !shouldTrimStatus(content)
}

View File

@ -310,7 +310,7 @@ class StatusViewHelper(private val itemView: View) {
}
companion object {
val COLLAPSE_INPUT_FILTER = arrayOf<InputFilter>(SmartLengthInputFilter.INSTANCE)
val COLLAPSE_INPUT_FILTER = arrayOf<InputFilter>(SmartLengthInputFilter)
val NO_INPUT_FILTER = arrayOfNulls<InputFilter>(0)
}
}

View File

@ -58,10 +58,7 @@ public final class ViewDataUtils {
.setApplication(visibleStatus.getApplication())
.setStatusEmojis(visibleStatus.getEmojis())
.setAccountEmojis(visibleStatus.getAccount().getEmojis())
.setCollapsible(!SmartLengthInputFilter.hasBadRatio(
visibleStatus.getContent(),
SmartLengthInputFilter.LENGTH_DEFAULT
))
.setCollapsible(!SmartLengthInputFilterKt.shouldTrimStatus(visibleStatus.getContent()))
.setCollapsed(true)
.setPoll(visibleStatus.getPoll())
.setCard(visibleStatus.getCard())