JoshHeaps.Net/wwwroot/js/casino/holdem/main.js

@@ -96,6 +96,19 @@ document.addEventListener("DOMContentLoaded", () => {
             });
         },
 
+        // Two players change chairs. Undoable like every other seat action, because a
+        // swap is easy to aim wrong and the seats look alike at a glance.
+        swapSeats: (from, to) => {
+            const movedName = nameOf(from);
+            const intoName = nameOf(to);
+            const wasEmpty = Render.isEmptySeat(state.seats[to]);
+            runUndoable(
+                wasEmpty
+                    ? `${movedName} moved to seat ${to + 1}.`
+                    : `${movedName} and ${intoName} changed seats.`,
+                () => HoldemState.swapSeats(state, from, to));
+        },
+
         makeDealer: index => {
             // Before the deal there's nothing posted, so this is just moving a marker.
             // After it, the blinds have to follow the button or the badges and the

JoshHeaps.Net/wwwroot/js/casino/holdem/render.js

@@ -49,11 +49,21 @@ const Render = {
         document.getElementById("defaultStackInput").value = this.state.defaultStack ?? "";
     },
 
+    // Whether this device can actually drag a seat. HTML5 drag events are never
+    // generated from a touch screen, so on a phone the last clause of the hint below
+    // described something impossible — on the device the rest of the sentence was
+    // written for. Touch gets told about the menu route instead, which works.
+    canDragSeats() {
+        return typeof matchMedia !== "function" || matchMedia("(hover: hover)").matches;
+    },
+
     renderTableHint() {
         const hint = document.getElementById("tableHint");
         // Gestures are invisible until someone tells you about them, and this is the
         // only place on the table with room to say so.
-        hint.textContent = "Tap a seat to edit · double-tap to fold · press and hold for quick actions · drag to swap seats.";
+        hint.textContent = this.canDragSeats()
+            ? "Tap a seat to edit · double-tap to fold · press and hold for quick actions · drag to swap seats."
+            : "Tap a seat to edit · double-tap to fold · press and hold for quick actions, including moving a seat.";
     },
 
     renderNotes() {

JoshHeaps.Net/wwwroot/js/casino/holdem/seatMenu.js

@@ -6,10 +6,16 @@ const SeatMenu = {
     hooks: null,
     seatIndex: null,
 
+    mode: null,
+
     open(state, hooks, seatIndex) {
         this.state = state;
         this.hooks = hooks;
         this.seatIndex = seatIndex;
+        // Always the action list, never whatever the sheet was showing when it last
+        // closed — a seat menu that opens on a list of chairs is a menu that lost the
+        // dealer's place.
+        this.mode = null;
         this.render();
         document.getElementById("seatMenuOverlay").hidden = false;
     },
@@ -63,29 +69,81 @@ const SeatMenu = {
             }
         }
 
+        // Changing chairs was drag-and-drop only, and HTML5 drag events are never
+        // generated from a touch screen — so on the device this tool is mostly used on,
+        // the "drag to swap seats" the hint advertised did nothing at all. This is the
+        // same move, by the route a thumb can actually take.
+        if (this.state.seats.length > 1) {
+            actions.push({ label: "Move to…", run: () => this.openMovePicker() });
+        }
+
         actions.push({ label: "Edit seat…", run: () => this.hooks.editSeat(index) });
         return actions;
     },
 
+    // The chairs this player could move to. Every other chair: swapping into an empty
+    // one is how a player moves, and swapping with an occupied one is two players
+    // changing places, which is the other half of the same job.
+    destinationsFor(index) {
+        return this.state.seats
+            .map((player, seat) => ({ player, seat }))
+            .filter(entry => entry.seat !== index);
+    },
+
+    openMovePicker() {
+        this.mode = "move";
+        this.render();
+    },
+
     render() {
         const player = this.state.seats[this.seatIndex];
-        document.getElementById("seatMenuTitle").textContent = HoldemState.displayName(player, this.seatIndex);
+        const title = document.getElementById("seatMenuTitle");
+        const subtitle = document.getElementById("seatMenuSubtitle");
+        const list = document.getElementById("seatMenuActions");
+        list.innerHTML = "";
+
+        if (this.mode === "move") {
+            title.textContent = `Move ${HoldemState.displayName(player, this.seatIndex)} to…`;
+            subtitle.textContent = "Their chips, cards and bet go with them. The button and the blinds stay on the chair.";
+            this.destinationsFor(this.seatIndex).forEach(({ player: other, seat }) => {
+                const btn = document.createElement("button");
+                btn.type = "button";
+                btn.className = "seatMenuBtn";
+                // displayName falls back to "Seat 5" for a chair with nobody in it,
+                // which reads as "Seat 5 — Seat 5". An empty chair says it's empty.
+                const named = (other.name || "").trim();
+                btn.textContent = named ? `Seat ${seat + 1} — ${named}` : `Seat ${seat + 1} — empty`;
+                btn.addEventListener("click", () => {
+                    const from = this.seatIndex;
+                    this.close();
+                    this.hooks.swapSeats(from, seat);
+                });
+                list.appendChild(btn);
+            });
+            return;
+        }
+
+        title.textContent = HoldemState.displayName(player, this.seatIndex);
 
         const stack = Betting.stackOf(this.state, player);
         const owed = Betting.toCall(this.state, player);
         const bits = [];
         if (stack > 0) bits.push(`${Money.format(stack)} behind`);
         if (owed > 0) bits.push(`${Money.format(owed)} to call`);
-        document.getElementById("seatMenuSubtitle").textContent = bits.join(" · ");
+        subtitle.textContent = bits.join(" · ");
 
-        const list = document.getElementById("seatMenuActions");
-        list.innerHTML = "";
         this.actionsFor(player, this.seatIndex).forEach(action => {
             const btn = document.createElement("button");
             btn.type = "button";
             btn.className = `seatMenuBtn ${action.className || ""}`;
             btn.textContent = action.label;
             btn.addEventListener("click", () => {
+                // "Move to…" stays on the sheet and swaps it for the seat list; every
+                // other action is the end of the interaction.
+                if (action.label === "Move to…") {
+                    action.run();
+                    return;
+                }
                 this.close();
                 action.run();
             });

JoshHeaps.Net/wwwroot/js/casino/holdem/state.js

@@ -467,6 +467,21 @@ const HoldemState = {
             .sort((a, b) => b.net - a.net);
     },
 
+    // Two players change chairs.
+    //
+    // The whole seat moves — name, stack, cards, what they have in the pot — because
+    // that is what changing chairs is. What stays behind is everything that belongs to
+    // the *position*: the button, the blinds and the acting index all name a chair, and
+    // a player who moves into the big blind's chair is the big blind. That is the same
+    // answer a card room gives.
+    swapSeats(state, a, b) {
+        const seats = state.seats || [];
+        if (a === b) return false;
+        if (!seats[a] || !seats[b]) return false;
+        [seats[a], seats[b]] = [seats[b], seats[a]];
+        return true;
+    },
+
     // The one check a banker actually needs, and the one nothing here did.
     //
     // Every chip on the table is a promise to pay cash for it later. If the chips in

tests/holdem/swapSeats.test.js

@@ -0,0 +1,95 @@
+// Two players changing chairs.
+const test = require("node:test");
+const assert = require("node:assert");
+const { Betting, HoldemState, makeTable, chipsOnTable } = require("./load");
+
+test("the whole seat moves", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2], stack: 100 });
+    state.seats[0].name = "Ann";
+    state.seats[0].cards = ["AS", "KD"];
+    state.seats[0].stack = 175;
+    state.seats[4].name = "";
+
+    HoldemState.swapSeats(state, 0, 4);
+
+    assert.equal(state.seats[4].name, "Ann");
+    assert.deepEqual(state.seats[4].cards, ["AS", "KD"]);
+    assert.equal(state.seats[4].stack, 175);
+    assert.equal(state.seats[0].name, "");
+});
+
+test("what they have in the pot goes with them", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2], stack: 100 });
+    Betting.beginHand(state);
+    const posted = state.seats.map(p => p.committed);
+    const before = chipsOnTable(state);
+
+    HoldemState.swapSeats(state, 1, 4);
+
+    assert.equal(state.seats[4].committed, posted[1]);
+    assert.equal(state.seats[1].committed, posted[4]);
+    assert.equal(chipsOnTable(state), before, "a swap never creates or destroys a chip");
+});
+
+test("the button stays on the chair, not on the player", () => {
+    // A card room moves the button around the table, not around the people. Somebody
+    // who sits down in the big blind's chair is the big blind.
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2], stack: 100, dealerSeatIndex: 0 });
+    state.seats[0].name = "Ann";
+
+    HoldemState.swapSeats(state, 0, 2);
+
+    assert.equal(state.dealerSeatIndex, 0);
+    assert.notEqual(state.seats[0].name, "Ann");
+});
+
+test("the blinds follow the chairs too", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
+    Betting.beginHand(state);
+    const before = HoldemState.getBlindSeats(state);
+
+    HoldemState.swapSeats(state, before.sbIndex, before.bbIndex);
+    const after = HoldemState.getBlindSeats(state);
+
+    assert.equal(after.sbIndex, before.sbIndex);
+    assert.equal(after.bbIndex, before.bbIndex);
+});
+
+test("swapping a seat with itself does nothing and says so", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1], stack: 100 });
+    const before = JSON.stringify(state);
+
+    assert.equal(HoldemState.swapSeats(state, 1, 1), false);
+    assert.equal(JSON.stringify(state), before);
+});
+
+test("a chair that isn't there is refused rather than swallowed", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1], stack: 100 });
+    const before = JSON.stringify(state);
+
+    assert.equal(HoldemState.swapSeats(state, 0, 99), false);
+    assert.equal(HoldemState.swapSeats(state, -1, 0), false);
+    assert.equal(JSON.stringify(state), before);
+});
+
+test("swapping twice puts everything back", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], stack: 100 });
+    Betting.beginHand(state);
+    const before = JSON.stringify(state);
+
+    HoldemState.swapSeats(state, 1, 3);
+    HoldemState.swapSeats(state, 1, 3);
+
+    assert.equal(JSON.stringify(state), before);
+});
+
+test("moving into an empty chair leaves an empty chair behind", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1], stack: 100 });
+    state.seats[1].name = "Ben";
+
+    HoldemState.swapSeats(state, 1, 5);
+
+    assert.equal(state.seats[5].name, "Ben");
+    assert.equal(state.seats[5].inHand, true);
+    assert.equal(state.seats[1].inHand, false);
+});

tests/holdem/uiAudit.js

@@ -522,8 +522,15 @@ const LayoutAudit = {
         const chips = [...document.querySelectorAll(".dealerChip")];
         const shown = chips.filter(chip => {
             const style = getComputedStyle(chip);
-            return style.display !== "none" && style.visibility !== "hidden" &&
+            if (style.display === "none" || style.visibility === "hidden") return false;
-                parseFloat(style.opacity) > 0.05;
+            if (parseFloat(style.opacity) <= 0.05) return false;
+            // A hovered seat deliberately fades its empty slot in — that's the "put the
+            // button here" preview, and it is on screen because a pointer is sitting on
+            // that seat. Counting it reports two buttons whenever the mouse happens to
+            // rest on the table, which is most of the time a mouse exists.
+            const seat = chip.closest(".seat");
+            if (seat && seat.matches(":hover") && !chip.classList.contains("active")) return false;
+            return true;
         });
         const offenders = [];