UiMessageContent.java

package com.kescoode.xmail.domain.internal;

import com.fsck.k9.mail.Part;

import java.util.List;

/**
 * {@link com.kescoode.xmail.domain.LocalEmail}对应的页面显示逻辑对象
 *
 * @author Kesco Lin
 */
public class UiMessageContent {

    public final String text;
    public final String html;
    public final List<Part> attachments;

    public UiMessageContent(String text, String html, List<Part> attachments) {
        this.text = text;
        this.html = html;
        this.attachments = attachments;
    }

    public String calculateContentPreview(String text) {
        if (text == null) {
            return null;
        }

        // Only look at the first 8k of a message when calculating
        // the preview.  This should avoid unnecessary
        // memory usage on large messages
        if (text.length() > 8192) {
            text = text.substring(0, 8192);
        }

        // Remove (correctly delimited by '-- \n') signatures
        text = text.replaceAll("(?ms)^-- [\\r\\n]+.*", "");
        // try to remove lines of dashes in the preview
        text = text.replaceAll("(?m)^----.*?$", "");
        // remove quoted text from the preview
        text = text.replaceAll("(?m)^[#>].*$", "");
        // Remove a common quote header from the preview
        text = text.replaceAll("(?m)^On .*wrote.?$", "");
        // Remove a more generic quote header from the preview
        text = text.replaceAll("(?m)^.*\\w+:$", "");
        // Remove horizontal rules.
        text = text.replaceAll("\\s*([-=_]{30,}+)\\s*", " ");

        // URLs in the preview should just be shown as "..." - They're not
        // clickable and they usually overwhelm the preview
        text = text.replaceAll("https?://\\S+", "...");
        // Don't show newlines in the preview
        text = text.replaceAll("(\\r|\\n)+", " ");
        // Collapse whitespace in the preview
        text = text.replaceAll("\\s+", " ");
        // Remove any whitespace at the beginning and end of the string.
        text = text.trim();

        return (text.length() <= 512) ? text : text.substring(0, 512);
    }

}