BangleApps/apps/txtreader/app.js

88 lines
2.9 KiB
JavaScript

function showFileSelector() {
let files = require("Storage").list().filter(f => f.endsWith('.txt'));
let menuItems = {};
files.forEach(file => {
menuItems[file] = () => {
E.showPrompt(`Select ${file}?`).then(confirm => {
if (confirm) {
onFileSelected(file);
} else {
showFileSelector();
}
});
};
});
menuItems['< Back'] = () => { load(); };
E.showMenu(menuItems);
}
function onFileSelected(file) {
const chunkSize = 1024;
let currentOffset = 0;
let currentPage = 1;
let history = [];
function displayText(offset, pageNumber) {
g.clear();
g.setFont("6x8", 1);
g.setColor(g.theme.fg);
g.drawString("Page " + pageNumber, 10, 2);
//g.drawString("Offset " + offset, 60, 2);
g.drawString(file, g.getWidth() - file.length * 6, 2);
var text = require("Storage").read(file, offset, chunkSize);
var lines = text.split("\n");
var y = 15; // Text start, top row reserved for page number
var linesDisplayed = 0; // Lines per page
var totalCharsDisplayed = 0; // Total characters per page
for (var i = 0; i < lines.length; i++) {
var wrappedLines = g.wrapString(lines[i], g.getWidth() - 20);
for (var j = 0; j < wrappedLines.length; j++) {
g.drawString(wrappedLines[j], 10, y);
y += 10; // Move down for the next line
linesDisplayed++;
totalCharsDisplayed += wrappedLines[j].length + (j < wrappedLines.length - 1 ? 0 : 1); // Add newline character for the last wrapped line
if (y >= g.getHeight() - 10) {
// If we run out of space, stop drawing
return { nextOffset: offset + totalCharsDisplayed, linesDisplayed: linesDisplayed };
}
}
}
return null; // No more lines to display
}
// Initial display
var result = displayText(currentOffset, currentPage);
history.push({ offset: currentOffset, linesDisplayed: result.linesDisplayed });
// Handle touch events
Bangle.on('touch', function(button) {
if (button === 2) { // Right side of the screen (next page)
var nextOffset = displayText(currentOffset, currentPage + 1);
if (nextOffset !== null) {
currentOffset = nextOffset.nextOffset;
currentPage++;
history.push({ offset: currentOffset, linesDisplayed: nextOffset.linesDisplayed });
displayText(currentOffset, currentPage);
} else {
currentOffset = 0;
currentPage = 1;
history = [{ offset: currentOffset, linesDisplayed: result.linesDisplayed }];
displayText(currentOffset, currentPage);
}
} else if (button === 1) { // Left side of the screen (previous page)
if (currentPage > 1) {
history.pop(); // Remove current page from history
var previousPage = history[history.length - 1];
currentOffset = previousPage.offset;
currentPage--;
displayText(currentOffset, currentPage);
}
}
});
}
showFileSelector();