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 headermain
HellPie
5 years ago
committed by
Konrad Pozniak
parent
246956bee1
commit
4ec0c182f7
@ -1,154 +0,0 @@ |
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/* |
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* Copyright 2018 Diego Rossi (@_HellPie) |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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package com.keylesspalace.tusky.util; |
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import android.text.InputFilter; |
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import android.text.SpannableStringBuilder; |
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import android.text.Spanned; |
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|
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/** |
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* A customized version of {@link android.text.InputFilter.LengthFilter} which allows smarter |
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* constraints and adds better visuals such as: |
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* <ul> |
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* <li>Ellipsis at the end of the constrained text to show continuation.</li> |
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* <li>Trimming of invisible characters (new lines, spaces, etc.) from the constrained text.</li> |
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* <li>Constraints end at the end of the last "word", before a whitespace.</li> |
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* <li>Expansion of the limit by up to 10 characters to facilitate the previous constraint.</li> |
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* <li>Constraints are not applied if the percentage of hidden content is too small.</li> |
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* </ul> |
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* |
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* Some of these features are configurable through at instancing time. |
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*/ |
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public class SmartLengthInputFilter implements InputFilter { |
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/** |
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* Defines how many characters to extend beyond the limit to cut at the end of the word on the |
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* boundary of it rather than cutting at the word preceding that one. |
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*/ |
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private static final int RUNWAY = 10; |
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/** |
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* Default for maximum status length on Mastodon and default collapsing length on Pleroma. |
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*/ |
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public static final int LENGTH_DEFAULT = 500; |
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/** |
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* Stores a reusable singleton instance of a {@link SmartLengthInputFilter} already configured |
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* to the default maximum length of {@value #LENGTH_DEFAULT}. |
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*/ |
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public static final SmartLengthInputFilter INSTANCE = new SmartLengthInputFilter(LENGTH_DEFAULT); |
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private final int max; |
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private final boolean allowRunway; |
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private final boolean skipIfBadRatio; |
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/** |
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* Creates a new {@link SmartLengthInputFilter} instance with a predefined maximum length and |
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* all the smart constraint features this class supports. |
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* |
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* @param max The maximum length before trimming. May change based on other constraints. |
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*/ |
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public SmartLengthInputFilter(int max) { |
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this(max, true, true); |
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} |
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/** |
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* Fully configures a new {@link SmartLengthInputFilter} to fine tune the state of the supported |
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* smart constraints this class supports. |
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* |
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* @param max The maximum length before trimming. |
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* @param allowRunway Whether to extend {@param max} by an extra 10 characters |
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* and trim precisely at the end of the closest word. |
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* @param skipIfBadRatio Whether to skip trimming entirely if the trimmed content |
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* will be less than 25% of the shown content. |
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*/ |
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public SmartLengthInputFilter(int max, boolean allowRunway, boolean skipIfBadRatio) { |
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this.max = max; |
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this.allowRunway = allowRunway; |
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this.skipIfBadRatio = skipIfBadRatio; |
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} |
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/** |
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* Calculates if it's worth trimming the message at a specific limit or if the content that will |
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* be hidden will not be enough to justify the operation. |
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* |
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* @param message The message to trim. |
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* @param limit The maximum length after trimming. |
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* @return Whether the message should be trimmed or not. |
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*/ |
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public static boolean hasBadRatio(Spanned message, int limit) { |
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return (double) limit / message.length() > 0.75; |
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} |
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/** {@inheritDoc} */ |
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@Override |
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public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) { |
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// Code originally imported from InputFilter.LengthFilter but heavily customized.
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// https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/text/InputFilter.java#175
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int sourceLength = source.length(); |
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int keep = max - (dest.length() - (dend - dstart)); |
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if (keep <= 0) return ""; |
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if (keep >= end - start) return null; // keep original
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keep += start; |
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// Enable skipping trimming if the ratio is not good enough
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if (skipIfBadRatio && (double)keep / sourceLength > 0.75) |
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return null; |
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// Enable trimming at the end of the closest word if possible
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if (allowRunway && Character.isLetterOrDigit(source.charAt(keep))) { |
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int boundary; |
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// Android N+ offer a clone of the ICU APIs in Java for better internationalization and
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// unicode support. Using the ICU version of BreakIterator grants better support for
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// those without having to add the ICU4J library at a minimum Api trade-off.
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if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) { |
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android.icu.text.BreakIterator iterator = android.icu.text.BreakIterator.getWordInstance(); |
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iterator.setText(source.toString()); |
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boundary = iterator.following(keep); |
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if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep); |
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} else { |
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java.text.BreakIterator iterator = java.text.BreakIterator.getWordInstance(); |
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iterator.setText(source.toString()); |
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boundary = iterator.following(keep); |
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if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep); |
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} |
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keep = boundary; |
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} else { |
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// If no runway is allowed simply remove whitespaces if present
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while (Character.isWhitespace(source.charAt(keep - 1))) { |
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--keep; |
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if (keep == start) return ""; |
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} |
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} |
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if (Character.isHighSurrogate(source.charAt(keep - 1))) { |
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--keep; |
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if (keep == start) return ""; |
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} |
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if (source instanceof Spanned) { |
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return new SpannableStringBuilder(source, start, keep).append("…"); |
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} else { |
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return source.subSequence(start, keep) + "…"; |
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} |
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} |
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} |
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@ -0,0 +1,111 @@ |
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/* Copyright 2019 Tusky contributors |
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* |
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* This file is a part of Tusky. |
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* |
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* This program is free software; you can redistribute it and/or modify it under the terms of the |
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* GNU General Public License as published by the Free Software Foundation; either version 3 of the |
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* License, or (at your option) any later version. |
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* |
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* Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even |
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* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
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* Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License along with Tusky; if not, |
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* see <http://www.gnu.org/licenses>. */ |
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package com.keylesspalace.tusky.util |
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import android.text.InputFilter |
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import android.text.SpannableStringBuilder |
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import android.text.Spanned |
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/** |
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* Defines how many characters to extend beyond the limit to cut at the end of the word on the |
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* boundary of it rather than cutting at the word preceding that one. |
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*/ |
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private const val RUNWAY = 10 |
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/** |
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* Default for maximum status length on Mastodon and default collapsing length on Pleroma. |
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*/ |
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private const val LENGTH_DEFAULT = 500 |
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|
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/** |
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* Calculates if it's worth trimming the message at a specific limit or if the content that will |
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* be hidden will not be enough to justify the operation. |
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* |
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* @param message The message to trim. |
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* @return Whether the message should be trimmed or not. |
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*/ |
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fun shouldTrimStatus(message: Spanned): Boolean { |
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return LENGTH_DEFAULT / message.length > 0.75 |
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} |
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/** |
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* A customized version of {@link android.text.InputFilter.LengthFilter} which allows smarter |
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* constraints and adds better visuals such as: |
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* <ul> |
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* <li>Ellipsis at the end of the constrained text to show continuation.</li> |
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* <li>Trimming of invisible characters (new lines, spaces, etc.) from the constrained text.</li> |
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* <li>Constraints end at the end of the last "word", before a whitespace.</li> |
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* <li>Expansion of the limit by up to 10 characters to facilitate the previous constraint.</li> |
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* <li>Constraints are not applied if the percentage of hidden content is too small.</li> |
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* </ul> |
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*/ |
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object SmartLengthInputFilter : InputFilter { |
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/** {@inheritDoc} */ |
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override fun filter(source: CharSequence, start: Int, end: Int, dest: Spanned, dstart: Int, dend: Int): CharSequence? { |
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// Code originally imported from InputFilter.LengthFilter but heavily customized and converted to Kotlin. |
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// https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/text/InputFilter.java#175 |
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val sourceLength = source.length |
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var keep = LENGTH_DEFAULT - dest.length - dend - dstart |
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if (keep <= 0) return "" |
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if (keep >= end - start) return null // Keep original |
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keep += start |
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// Skip trimming if the ratio doesn't warrant it |
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if (keep.toDouble() / sourceLength > 0.75) return null |
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// Enable trimming at the end of the closest word if possible |
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if (source[keep].isLetterOrDigit()) { |
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var boundary: Int |
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// Android N+ offer a clone of the ICU APIs in Java for better internationalization and |
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// unicode support. Using the ICU version of BreakIterator grants better support for |
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// those without having to add the ICU4J library at a minimum Api trade-off. |
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if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) { |
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val iterator = android.icu.text.BreakIterator.getWordInstance() |
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iterator.setText(source.toString()) |
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boundary = iterator.following(keep) |
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if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep) |
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} else { |
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val iterator = java.text.BreakIterator.getWordInstance() |
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iterator.setText(source.toString()) |
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boundary = iterator.following(keep) |
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if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep) |
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} |
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keep = boundary |
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} else { |
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// If no runway is allowed simply remove whitespaces if present |
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while(source[keep - 1].isWhitespace()) { |
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--keep |
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if (keep == start) return "" |
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} |
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} |
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if (source[keep - 1].isHighSurrogate()) { |
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--keep |
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if (keep == start) return "" |
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} |
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return if (source is Spanned) { |
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SpannableStringBuilder(source, start, keep).append("…") |
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} else { |
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"${source.subSequence(start, keep)}…" |
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} |
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} |
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} |
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