Source:
<code>public void displayMessageViewContainer(MessageViewInfo messageViewInfo, final OnRenderingFinishedListener onRenderingFinishedListener, boolean automaticallyLoadPictures, boolean hideUnsignedTextDivider, AttachmentViewCallback attachmentCallback) { this.attachmentCallback = attachmentCallback; resetView(); renderAttachments(messageViewInfo); if (mSavedState != null) { if (mSavedState.showingPictures) { setLoadPictures(true); } mSavedState = null; } String textToDisplay = K9.displayAsPlaintText() <START> ? HtmlConverter.htmlToText(messageViewInfo.text) <END> : messageViewInfo.text; if (textToDisplay != null && !isShowingPictures()) { if (Utility.hasExternalImages(textToDisplay)) { if (automaticallyLoadPictures) { setLoadPictures(true); } else { hasHiddenExternalImages = true; } } } if (textToDisplay == null) { textToDisplay = HtmlConverter.wrapStatusMessage(getContext().getString(R.string.webview_empty_message)); } OnPageFinishedListener onPageFinishedListener = new OnPageFinishedListener() { @Override public void onPageFinished() { onRenderingFinishedListener.onLoadFinished(); } }; displayHtmlContentWithInlineAttachments( textToDisplay, messageViewInfo.attachmentResolver, onPageFinishedListener); if (!TextUtils.isEmpty(messageViewInfo.extraText)) { unsignedTextContainer.setVisibility(View.VISIBLE); unsignedTextDivider.setVisibility(hideUnsignedTextDivider ? View.GONE : View.VISIBLE); unsignedText.setText(messageViewInfo.extraText); } }</code><technical_language>This is want show, scrunched html text actual text/plain part if any. text displayed text field ViewableExtractedText, please MessageViewInfoExtractor for relevant code</technical_language>

Target:
public void displayMessageViewContainer(MessageViewInfo messageViewInfo, final OnRenderingFinishedListener onRenderingFinishedListener, boolean automaticallyLoadPictures, boolean hideUnsignedTextDivider, AttachmentViewCallback attachmentCallback) { this.attachmentCallback = attachmentCallback; resetView(); renderAttachments(messageViewInfo); if (mSavedState != null) { if (mSavedState.showingPictures) { setLoadPictures(true); } mSavedState = null; } String textToDisplay; boolean isPlainText = K9.displayAsPlaintText(); if(!isPlainText) textToDisplay = messageViewInfo.text; else textToDisplay = ""; if (textToDisplay != null && !isShowingPictures()) { if (Utility.hasExternalImages(textToDisplay)) { if (automaticallyLoadPictures) { setLoadPictures(true); } else { hasHiddenExternalImages = true; } } } if (textToDisplay == null) { textToDisplay = HtmlConverter.wrapStatusMessage(getContext().getString(R.string.webview_empty_message)); } OnPageFinishedListener onPageFinishedListener = new OnPageFinishedListener() { @Override public void onPageFinished() { onRenderingFinishedListener.onLoadFinished(); } }; displayHtmlContentWithInlineAttachments( textToDisplay, messageViewInfo.attachmentResolver, onPageFinishedListener); if(isPlainText) { plainTextContainer.setVisibility(View.VISIBLE); plainTextDivider.setVisibility(View.VISIBLE); plainText.setText(messageViewInfo.plainText); } if (!TextUtils.isEmpty(messageViewInfo.extraText)) { unsignedTextContainer.setVisibility(View.VISIBLE); unsignedTextDivider.setVisibility(hideUnsignedTextDivider ? View.GONE : View.VISIBLE); unsignedText.setText(messageViewInfo.extraText); } }