Classroom_Desktop/config/plasma/lookandfeel/contents/layouts/org.kde.plasma.desktop-layout.js

// The Ekklesia Classroom desktop.
//
// Plasma runs this once, when a session has no panel yet, and again on
// demand — `plasma-apply-lookandfeel -a org.ekklesia.classroom.desktop
// --resetLayout` rebuilds the whole desktop from this file. That is the
// classroom's recovery path for a damaged shell, and it is Plasma's own
// mechanism rather than something written here.
//
// One full-width bar along the bottom. Left is auxiliary, the middle is
// applications, the right is the small amount of status a teacher needs.
// Nothing else is on the screen.

var WALLPAPER = "/usr/share/backgrounds/ekklesia/classroom-calm.png";

// Matches the 76px strip the classroom has always used, so muscle memory
// and the room's viewing distance both carry over.
var PANEL_HEIGHT = 76;

// The idle desktop: the wallpaper, and nothing on it.
var screens = desktops();
for (var i = 0; i < screens.length; i++) {
    var desktop = screens[i];
    desktop.wallpaperPlugin = "org.kde.image";
    desktop.currentConfigGroup = ["Wallpaper", "org.kde.image", "General"];
    desktop.writeConfig("Image", "file://" + WALLPAPER);
    desktop.writeConfig("SlidePaths", "");
    // 2 is "scaled and cropped": the landscape fills the display at any
    // aspect ratio without being stretched out of shape.
    desktop.writeConfig("FillMode", 2);
    desktop.reloadConfig();
}

var panel = new Panel();
panel.location = "bottom";
panel.height = PANEL_HEIGHT;
panel.hiding = "none";
panel.floating = false;
panel.lengthMode = "fill";
panel.alignment = "center";
panel.opacity = "adaptive";

// LEFT — auxiliary. Parent Call is not one of the room's applications and
// is deliberately not in the row with them.
// Quick Launch: a launcher, and only a launcher.
//
// Two other widgets were tried on a real panel. The Icon widget copies
// the desktop entry into the user's home and uses the copy, so an update
// could never change the icon or the command — it kept showing a bell out
// of a package that no longer contained one. A task manager reads
// /usr/share/applications live, which fixes that, but a task manager also
// shows every running window, so the auxiliary corner filled up with the
// lesson's tasks.
//
// Quick Launch reads the entry live and shows nothing but the button.
var parentCall = panel.addWidget("org.kde.plasma.quicklaunch");
parentCall.currentConfigGroup = ["General"];
// A file URL, not applications:. Quick Launch resolves the entry itself
// and does not copy it, so the path is a live reference to what the
// package installs.
parentCall.writeConfig(
    "launcherUrls",
    "file:///usr/share/applications/ekklesia-parent-call.desktop"
);
parentCall.writeConfig("showLauncherNames", false);
parentCall.writeConfig("enablePopup", false);
parentCall.writeConfig("maxSectionCount", 1);

var leftGap = panel.addWidget("org.kde.plasma.panelspacer");
leftGap.currentConfigGroup = ["General"];
leftGap.writeConfig("expanding", true);

// CENTRE — the applications, and the whole of the running/minimised/active
// story. This applet is the reason the classroom stops writing a dock.
var tasks = panel.addWidget("org.kde.plasma.icontasks");
tasks.currentConfigGroup = ["General"];
// The DVD line is rewritten by classroom-provision to match the machine:
// a room with no optical drive has it removed, so no teacher is offered a
// disc player that cannot exist. Between the marker comments, and nowhere
// else, so the edit is a line replacement and not a parse.
tasks.writeConfig("launchers", [
    "applications:ekklesia-wonderink.desktop",
    "applications:google-chrome.desktop",
    /* CLASSROOM-DVD-LAUNCHER */ "applications:ekklesia-dvd.desktop"
].join(","));
// Every window gets its own button. Teachers should never have to open a
// group to find out that a second window exists.
tasks.writeConfig("groupingStrategy", 0);
tasks.writeConfig("showOnlyCurrentDesktop", false);
tasks.writeConfig("showOnlyCurrentActivity", false);
tasks.writeConfig("showOnlyCurrentScreen", false);
// Clicking a button always means "show me this", and never "hide it".
//
// This was measured before it was decided. Plasma 6.3 draws a minimised
// task and a task that is merely behind another window identically: no
// indicator for closed, a grey indicator for running, a teal one for
// active — three marks for four states. Rather than write a task manager
// that draws a fourth, the classroom removes the state. There is nothing
// on the idle desktop for a teacher to want to see, so minimising an
// application in this room has no purpose and only ever loses it.
//
// A window minimised some other way is still shown as running and comes
// back with one click, so it can never be lost even then.
tasks.writeConfig("minimizeActiveTaskOnClick", false);
tasks.writeConfig("fill", false);
tasks.writeConfig("maxStripes", 1);
tasks.writeConfig("indicateAudioStreams", false);
tasks.writeConfig("wheelEnabled", false);
tasks.writeConfig("middleClickAction", "NewInstance");
tasks.writeConfig("showToolTips", true);
tasks.writeConfig("iconSpacing", 2);

var rightGap = panel.addWidget("org.kde.plasma.panelspacer");
rightGap.currentConfigGroup = ["General"];
rightGap.writeConfig("expanding", true);

// RIGHT — status.
//
// Three ordinary applets straight on the bar, and no system tray around
// them. A tray is a container that discovers whatever is installed and
// then hides most of it behind an arrow; measured in the lab it collected
// battery, brightness, clipboard, keyboard layout, camera, vaults and
// screen management on a machine that has none of those to say anything
// about. Naming the four the classroom actually uses is both smaller and
// deterministic, and it leaves nothing for a teacher to expand.
panel.addWidget("org.kde.plasma.networkmanagement");

var volume = panel.addWidget("org.kde.plasma.volume");
volume.currentConfigGroup = ["General"];
// No chime when the volume changes. A classroom is often listening to
// something when somebody adjusts it, and a beep over a lesson is worse
// than no feedback at all — the on-screen display is the feedback, and it
// is in the look and feel package where a television can read it.
//
// Plasma 6 moved this setting out of the applet and into a global one,
// and the applet migrates a false written here into it on first run. So
// this is both the setting and the instruction to carry it across.
volume.writeConfig("volumeFeedback", false);
volume.writeConfig("volumeOsd", true);
volume.writeConfig("muteOsd", true);
volume.writeConfig("outputChangeOsd", true);
// A teacher pressing the volume key expects a step they can hear.
volume.writeConfig("volumeStep", 5);

panel.addWidget("org.kde.plasma.notifications");

var clock = panel.addWidget("org.kde.plasma.digitalclock");
clock.currentConfigGroup = ["Appearance"];
clock.writeConfig("showDate", true);
clock.writeConfig("dateFormat", "custom");
clock.writeConfig("customDateFormat", "ddd d MMM");
clock.writeConfig("showSeconds", 0);
clock.writeConfig("dateDisplayFormat", "BelowTime");
// Sized by the bar, not by a number written here.
//
// It used to be pinned at 15 points to stop it becoming the largest text
// in the room. On a 4K television that was a clock a teacher could not
// read from the back of the room, and it was the one thing in the
// classroom that did not follow UI_SCALE, because a point size written
// into a layout is the same point size at every scale. Plasma's own
// sizing follows the bar, and the bar follows the scale.
clock.writeConfig("autoFontAndSize", true);
clock.writeConfig("fontWeight", 500);