Shows one email at a time in Gmail inbox, with enhanced email detection and accurate counter for empty inbox.
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// ==UserScript==
// @name Gmail Single Email View
// @namespace http://tampermonkey.net/
// @version 2.0 // Incremented version to signify major bug fix for counter
// @description Shows one email at a time in Gmail inbox, with enhanced email detection and accurate counter for empty inbox.
// @author Your Name
// @match https://mail.google.com/*
// @grant none
// ==/UserScript==
(function() {
'use strict';
let emailRows = [];
let currentIndex = 0;
let navControls;
let prevBtn, nextBtn, countDisplay;
let observer = null;
let updateTimeoutId = null;
let isPluginInitialized = false; // Flag to ensure initialization runs only once
/**
* Injects necessary CSS into the Gmail page to ensure elements can be hidden and essential UI remains visible.
*/
function injectCss() {
const styleId = 'single-email-view-style';
if (document.getElementById(styleId)) {
return; // Style already injected
}
const style = document.createElement('style');
style.id = styleId;
style.textContent = `
/* Styling for the plugin's navigation buttons */
#single-email-nav-controls {
position: fixed;
bottom: 20px;
left: 50%;
transform: translateX(-50%);
z-index: 10000; /* Ensure it's above Gmail's UI */
display: flex;
gap: 10px;
background-color: #fff;
padding: 10px 20px;
border-radius: 12px; /* Rounded corners */
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15); /* Soft shadow */
border: 1px solid #ddd;
}
#single-email-nav-controls button {
padding: 10px 20px;
font-size: 16px;
cursor: pointer;
border: none;
border-radius: 8px; /* Rounded corners for buttons */
background-color: #4285f4; /* Gmail blue */
color: white;
transition: background-color 0.2s ease-in-out, transform 0.1s ease-in-out;
box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
#single-email-nav-controls button:hover {
background-color: #357ae8; /* Darker blue on hover */
transform: translateY(-1px);
}
#single-email-nav-controls button:active {
background-color: #2a6ac3;
transform: translateY(0);
box-shadow: none;
}
#single-email-nav-controls button:disabled {
background-color: #cccccc;
cursor: not-allowed;
box-shadow: none;
}
/* Styling for the current email count display */
#email-count-display {
display: flex;
align-items: center;
justify-content: center;
min-width: 80px;
padding: 0 10px;
font-weight: bold;
color: #333;
}
/* IMPORTANT: Only hide email rows with this class to avoid hiding everything */
.single-email-hidden {
display: none !important;
}
/* Ensure essential Gmail UI components (like sidebars, toolbars) remain visible */
.nH.nn.aKz { /* Pagination/toolbar at the bottom */
display: flex !important; /* This should generally be flex */
}
.G-atb, .Cp { /* Top toolbar and category tabs */
display: block !important; /* These are usually block or flex */
}
/* Explicitly ensure left navigation sidebar is visible (but let internal layout be managed by Gmail) */
div[role="navigation"] { /* The main navigation sidebar container */
display: block !important;
}
`;
document.head.appendChild(style);
console.log('Gmail Single Email View: Injected CSS styles.');
}
/**
* Initializes the Gmail Single Email View plugin.
* Creates navigation controls using createElement to avoid TrustedHTML issues.
*/
function initGmailSingleEmailView() {
if (isPluginInitialized) {
console.log('Gmail Single Email View: Plugin already initialized, skipping.');
return;
}
console.log('Gmail Single Email View: Initializing plugin interface...');
injectCss(); // Ensure CSS is injected first
navControls = document.getElementById('single-email-nav-controls');
if (!navControls) {
navControls = document.createElement('div');
navControls.id = 'single-email-nav-controls';
document.body.appendChild(navControls);
console.log('Gmail Single Email View: Navigation controls container created and appended.');
// Create buttons and display element separately and append them
prevBtn = document.createElement('button');
prevBtn.id = 'prevEmailBtn';
prevBtn.textContent = 'Previous';
prevBtn.disabled = true; // Start disabled
navControls.appendChild(prevBtn);
countDisplay = document.createElement('div');
countDisplay.id = 'email-count-display';
navControls.appendChild(countDisplay);
nextBtn = document.createElement('button');
nextBtn.id = 'nextEmailBtn';
nextBtn.textContent = 'Next';
nextBtn.disabled = true; // Start disabled
navControls.appendChild(nextBtn);
console.log('Gmail Single Email View: Navigation buttons and display element created and appended.');
} else {
console.log('Gmail Single Email View: Navigation controls already exist.');
// If controls exist, just get references
prevBtn = document.getElementById('prevEmailBtn');
nextBtn = document.getElementById('nextEmailBtn');
countDisplay = document.getElementById('email-count-display');
}
addEventListeners();
updateEmailList();
isPluginInitialized = true; // Set flag after successful initialization
}
/**
* Adds event listeners to the navigation buttons.
*/
function addEventListeners() {
if (prevBtn && !prevBtn.hasAttribute('data-listener-added')) {
prevBtn.onclick = showPreviousEmail;
prevBtn.setAttribute('data-listener-added', 'true');
console.log('Gmail Single Email View: Previous button event listener added.');
}
if (nextBtn && !nextBtn.hasAttribute('data-listener-added')) {
nextBtn.onclick = showNextEmail;
nextBtn.setAttribute('data-listener-added', 'true');
console.log('Gmail Single Email View: Next button event listener added.');
}
}
/**
* Resets the plugin state when no emails are found.
* This ensures the counter correctly displays "No Emails Found".
*/
function resetPluginState() {
emailRows = []; // Clear the list of emails
currentIndex = 0; // Reset index
console.log('Gmail Single Email View: Resetting plugin state: no emails found.');
showEmail(0); // This will ensure all hidden emails are revealed, and internal display logic runs
updateButtonStates();
updateCountDisplay();
}
/**
* Updates the list of email rows and displays the current email.
*/
function updateEmailList() {
console.log('Gmail Single Email View: Scanning for email rows...');
let potentialEmailRows = [];
// Check if the "No new emails!" message is present
const noEmailsMessage = document.querySelector('div[role="main"] .nH.nZ.nn');
if (noEmailsMessage && noEmailsMessage.textContent.includes('No new emails!')) {
console.log('Gmail Single Email View: "No new emails!" message detected.');
resetPluginState(); // Call the dedicated reset function
return; // Exit early as there are no emails to process
}
// Primary selector based on your provided HTML structure
potentialEmailRows = Array.from(document.querySelectorAll('tr.zA.yO[role="row"]:has([role="checkbox"])'));
console.log(`Gmail Single Email View: Found ${potentialEmailRows.length} potential email rows with primary selector (tr.zA.yO[role="row"]:has([role="checkbox"])).`);
// If primary selector finds few or none, try other common patterns in Gmail
if (potentialEmailRows.length === 0 || potentialEmailRows.length < 5) {
console.log('Gmail Single Email View: Primary selector found few/no rows, trying alternative selectors...');
// Fallback to more general selectors if the primary one isn't fruitful
let altRows = Array.from(document.querySelectorAll('div[role="main"] tr[role="row"], .AO > .xY, [aria-labelledby^="thread_"], [aria-labelledby^="msg_"]'));
// Only use altRows if they find more results
if (altRows.length > potentialEmailRows.length) {
potentialEmailRows = altRows;
console.log(`Gmail Single Email View: Found ${potentialEmailRows.length} rows with alternative combined selectors.`);
}
}
// Filter out non-email rows (e.g., header, pagination, ads, empty message rows, non-email UI elements)
emailRows = potentialEmailRows.filter(row => {
// Check for elements characteristic of an actual email row:
const hasCheckbox = row.querySelector('[role="checkbox"]');
const hasGridcell = row.querySelector('[role="gridcell"]');
const isColumnHeader = row.querySelector('[role="columnheader"]');
// More robust subject/sender checks based on your HTML
const hasSubject = row.querySelector('.bog, .ts, .y6');
const hasSender = row.querySelector('.yP, .zF, .go');
// The row should look like email content AND not be a header.
// Require at least a checkbox, a gridcell, and EITHER a subject/sender.
const isEmailContentRow = hasCheckbox && hasGridcell && (hasSubject || hasSender) && !isColumnHeader;
// Explicitly exclude known non-email rows or UI elements that might get caught by broad selectors
const isKnownNonEmailUI = row.classList.contains('Cp') ||
row.classList.contains('nH') ||
row.classList.contains('G-atb') ||
row.classList.contains('Bu') ||
row.querySelector('.aeJ') ||
row.matches('.ads, .AP');
if (!isEmailContentRow || isKnownNonEmailUI) {
// console.log('Gmail Single Email View: Filtering out non-email row (lacks essential email characteristics or is known UI element):', row.outerHTML);
}
return isEmailContentRow && !isKnownNonEmailUI;
});
console.log(`Gmail Single Email View: Filtered down to ${emailRows.length} actual email rows.`);
// After filtering, if no emails are found, reset the plugin state
if (emailRows.length === 0) {
console.log('Gmail Single Email View: Filtered result is 0 emails. Calling resetPluginState.');
resetPluginState();
} else {
// If emails are found, proceed with normal display logic
// Adjust currentIndex if it's out of bounds after filtering
if (currentIndex >= emailRows.length) {
currentIndex = emailRows.length - 1;
} else if (currentIndex < 0) {
currentIndex = 0;
}
showEmail(currentIndex);
updateButtonStates();
updateCountDisplay();
}
}
/**
* Shows only the email at the given index and hides all others.
* @param {number} index - The index of the email to show.
*/
function showEmail(index) {
// Always ensure ALL previously hidden emails are made visible before re-hiding
document.querySelectorAll('.single-email-hidden').forEach(el => el.classList.remove('single-email-hidden'));
if (emailRows.length === 0) {
console.log('No email rows found to display, ensuring all elements are visible and buttons disabled.');
updateButtonStates(); // Ensure buttons are disabled
updateCountDisplay(); // Ensure counter says "No Emails Found"
return; // No emails to show, so nothing to hide
}
if (index < 0 || index >= emailRows.length) {
console.warn(`Attempted to show email at invalid index: ${index}. Clamping to valid range.`);
index = Math.max(0, Math.min(index, emailRows.length - 1));
}
emailRows.forEach((row, i) => {
if (i === index) {
row.classList.remove('single-email-hidden');
row.style.display = ''; // Ensure display is not explicitly set to none by previous operation
} else {
row.classList.add('single-email-hidden');
}
});
currentIndex = index;
updateButtonStates();
updateCountDisplay();
console.log(`Showing email ${currentIndex + 1} of ${emailRows.length}.`);
}
/**
* Shows the next email in the list.
*/
function showNextEmail() {
if (currentIndex < emailRows.length - 1) {
console.log('Moving to next email...');
showEmail(currentIndex + 1);
} else {
console.log('Already at the last email.');
}
}
/**
* Shows the previous email in the list.
*/
function showPreviousEmail() {
if (currentIndex > 0) {
console.log('Moving to previous email...');
showEmail(currentIndex - 1);
} else {
console.log('Already at the first email.');
}
}
/**
* Updates the disabled state of the navigation buttons.
*/
function updateButtonStates() {
if (prevBtn) {
prevBtn.disabled = currentIndex === 0 || emailRows.length === 0;
}
if (nextBtn) {
nextBtn.disabled = currentIndex >= emailRows.length - 1 || emailRows.length === 0;
}
}
/**
* Updates the display showing current email index and total count.
*/
function updateCountDisplay() {
if (countDisplay) {
countDisplay.textContent = emailRows.length > 0 ? `${currentIndex + 1} / ${emailRows.length}` : 'No Emails Found';
}
}
/**
* Observes the DOM for changes in Gmail.
* This function now observes the entire document body for stability.
*/
function setupMutationObserver() {
// Disconnect existing observer if it exists to prevent duplicates
if (observer) {
observer.disconnect();
console.log('Gmail Single Email View: Disconnected existing observer.');
}
isPluginInitialized = false; // Reset initialization flag on new observer setup
// Observe the entire document body for maximum robustness
observer = new MutationObserver((mutations) => {
// Check for relevant changes that would impact email list
const relevantChange = mutations.some(mutation =>
mutation.addedNodes.length > 0 && Array.from(mutation.addedNodes).some(node =>
node.nodeType === Node.ELEMENT_NODE &&
(node.matches('tr.zA.yO[role="row"]') || node.matches('.nH.nZ.nn')) // Check for new email rows or "No new emails!" message
) ||
mutation.removedNodes.length > 0 && Array.from(mutation.removedNodes).some(node =>
node.nodeType === Node.ELEMENT_NODE &&
(node.matches('tr.zA.yO[role="row"]') || node.matches('.nH.nZ.nn'))
) ||
// Also trigger if the immediate parent of email rows (the tbody or table) changes its children
(mutation.type === 'childList' && (mutation.target.matches('tbody') || mutation.target.matches('table.F.cf.zt')))
);
// Only re-scan if a relevant change occurred
if (relevantChange) {
clearTimeout(updateTimeoutId);
updateTimeoutId = setTimeout(() => {
console.log('Gmail Single Email View: DOM changes detected, re-scanning emails...');
initGmailSingleEmailView(); // Re-initialize to ensure state and elements are correct
}, 500);
}
});
observer.observe(document.body, { childList: true, subtree: true, attributes: false, characterData: false });
console.log('Gmail Single Email View: Started observing document.body for changes.');
// Initial call to initGmailSingleEmailView
initGmailSingleEmailView();
}
// Initial setup attempts
window.addEventListener('load', setupMutationObserver);
document.addEventListener('DOMContentLoaded', setupMutationObserver);
// Fallback for immediate execution if DOM is already ready
if (document.readyState === 'complete' || document.readyState === 'interactive') {
setupMutationObserver();
}
})();