chrome/android/features/autofill_assistant/java/src/org/chromium/chrome/browser/autofill_assistant/AssistantTextUtils.java

// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.chrome.browser.autofill_assistant;

import android.text.method.LinkMovementMethod;
import android.text.style.StyleSpan;
import android.widget.TextView;

import androidx.annotation.Nullable;

import org.chromium.base.Callback;
import org.chromium.ui.text.NoUnderlineClickableSpan;
import org.chromium.ui.text.SpanApplier;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Common text utilities used by autofill assistant.
 */
public class AssistantTextUtils {
    /** Bold tags of the form <b>...</b>. */
    private static final SpanApplier.SpanInfo BOLD_SPAN_INFO =
            new SpanApplier.SpanInfo("<b>", "</b>", new StyleSpan(android.graphics.Typeface.BOLD));
    /** Links of the form <link0>...</link0>. */
    private static final Pattern LINK_PATTERN = Pattern.compile("<link(\\d+)>");

    /**
     * Sets the text of {@code view} by automatically applying all special appearance tags in {@code
     * text}.
     *
     * Special appearance tags are of the form <b></b> or <link0></link0>. For links, a callback can
     * be provided.
     */
    public static void applyVisualAppearanceTags(
            TextView view, String text, @Nullable Callback<Integer> linkCallback) {
        List<SpanApplier.SpanInfo> spans = new ArrayList<>();
        if (text.contains("<b>")) {
            spans.add(BOLD_SPAN_INFO);
        }

        // We first collect the link IDs into a set to allow multiple links with same ID.
        Set<Integer> linkIds = new HashSet<>();
        Matcher matcher = LINK_PATTERN.matcher(text);
        while (matcher.find()) {
            linkIds.add(Integer.parseInt(matcher.group(1)));
        }

        for (Integer linkId : linkIds) {
            spans.add(new SpanApplier.SpanInfo("<link" + linkId + ">", "</link" + linkId + ">",
                    new NoUnderlineClickableSpan(view.getContext().getResources(), (unusedView) -> {
                        if (linkCallback != null) {
                            linkCallback.onResult(linkId);
                        }
                    })));
        }

        view.setText(SpanApplier.applySpans(
                text, spans.toArray(new SpanApplier.SpanInfo[spans.size()])));
        view.setMovementMethod(linkIds.isEmpty() ? null : LinkMovementMethod.getInstance());
    }
}