');
const freqStep = (band.end_freq - band.start_freq) / 40.0;
for (let i = 0; i <= 40; i++) {
if (i % 4 === 0) {
bandMarkersDiv.append("—" + ((band.start_freq + i * freqStep)/1000000).toFixed(3) + "
");
} else if (i % 4 === 2) {
bandMarkersDiv.append("–
");
}
}
// Prepare the spots list
var bandSpotsDiv = $("
");
var lastSpotPxDownBand = -999;
// Sort by frequency so have a consistent order in which to plan where they will appear on the band div.
spotList.sort(function(a, b) { return a.freq - b.freq; });
// First calculate how we should be displaying the spots. There are three "modes" to try to place them in a
// visually appealing way:
// 1) Spaced normally, not going over the end of the band, so we populate them forwards.
// 2) Would go over the end, but the spots don't fill the band, so we populate them backwards.
// 3) Spots totally fill the band (or more), so we space them evenly starting at the top.
// In each case, we don't add anything to the DOM yet, we just calculate "pxDownBandLabel" (how far the *top* of
// the label is from the top of the div) and add that as a property to the spot for later use.
if (spotList.length >= BAND_COLUMN_HEIGHT_PX / BAND_COLUMN_SPOT_DIV_HEIGHT_PX) {
// Mode 3.
// Just lay out all spots simply, starting at 0px offset and working down with each one touching.
lastSpotPxDownBand = 0 - BAND_COLUMN_SPOT_DIV_HEIGHT_PX;
spotList.forEach(s => {
lastSpotPxDownBand = lastSpotPxDownBand + BAND_COLUMN_SPOT_DIV_HEIGHT_PX;
s["pxDownBandLabel"] = lastSpotPxDownBand;
});
} else {
// Mode 1 or 2. Run through adding things to the list forwards as a test.
spotList.forEach(s => {
// Work out how far down the div to draw it
var percentDownBand = (s.freq - band.start_freq) / (band.end_freq - band.start_freq) * 0.97; // not 100% due to fudge, the first and last dashes are not exactly at the top and bottom of the div as some space is needed for text
var pxDownBand = percentDownBand * BAND_COLUMN_HEIGHT_PX;
if (pxDownBand < lastSpotPxDownBand + BAND_COLUMN_SPOT_DIV_HEIGHT_PX) {
pxDownBand = lastSpotPxDownBand + BAND_COLUMN_SPOT_DIV_HEIGHT_PX; // Prevent overlap
}
s["pxDownBandLabel"] = pxDownBand;
lastSpotPxDownBand = pxDownBand;
});
// Work out if we overflowed the end.
if (lastSpotPxDownBand <= BAND_COLUMN_HEIGHT_PX) {
// Mode 1. Current positions are fine and there's nothing to do.
} else {
// Mode 2. Repeat the process but backwards, starting at the end and working upwards.
lastSpotPxDownBand = 999999;
spotList.reverse().forEach(s => {
// Work out how far down the div to draw it
var percentDownBand = (s.freq - band.start_freq) / (band.end_freq - band.start_freq) * 0.97; // not 100% due to fudge, the first and last dashes are not exactly at the top and bottom of the div as some space is needed for text
var pxDownBand = percentDownBand * BAND_COLUMN_HEIGHT_PX;
if (pxDownBand > lastSpotPxDownBand - BAND_COLUMN_SPOT_DIV_HEIGHT_PX) {
pxDownBand = lastSpotPxDownBand - BAND_COLUMN_SPOT_DIV_HEIGHT_PX; // Prevent overlap
}
s["pxDownBandLabel"] = pxDownBand;
lastSpotPxDownBand = pxDownBand;
});
}
}
// Now each spot is tagged with how far down the div it should go, add them to the DOM.
spotList.forEach(s => {
bandSpotsDiv.append(`
${s.dx_call}${s.dx_call} ${(s.freq/1000000).toFixed(3)} ${s.mode}
`);
});
// Work out how tall the canvas should be. Normally this is matching the normal band column height, but if some
// spots have gone off the end of the band markers and stretched their div, we need to resize the canvas to
// match, otherwise we have nowhere to draw their connecting lines.
var canvasHeight = Math.max(BAND_COLUMN_HEIGHT_PX, lastSpotPxDownBand + BAND_COLUMN_SPOT_DIV_HEIGHT_PX);
maxHeightBand = Math.max(maxHeightBand, canvasHeight);
// Draw horizontal or diagonal lines to join up the "real" frequency with where the spot div ended up
var bandLinesCanvas = $(`