fix: support for seven segment set number

src/jdom/servers/registerserver.ts

@@ -144,8 +144,14 @@ export class JDRegisterServer<
         )
     }
 
+    /**
+     * Sets the value on the register
+     * @param values values to set
+     * @param skipChangeEvent true to avoid emitting CHANGE
+     * @returns true if values changed; false otherwise
+     */
     setValues(values: TValues, skipChangeEvent?: boolean) {
-        if (this.readOnly) return
+        if (this.readOnly) return false
 
         if (this.shouldNormalize()) this.normalize(values)
         if (this.valueProcessor) values = this.valueProcessor(values)
@@ -154,7 +160,10 @@ export class JDRegisterServer<
         if (!bufferEq(this.data, d)) {
             this.data = d
             if (!skipChangeEvent) this.emit(CHANGE)
+            return true
         }
+
+        return false
     }
 
     reset() {

src/servers/jacdac-servers.ts

@@ -43,3 +43,4 @@ export * from "./planarpositionserver"
 export * from "./serialserver"
 export * from "./rosserver"
 export * from "./indexedscreenserver"
+export * from "./sevensegmentdisplayserver"

src/servers/servers.ts

@@ -167,6 +167,7 @@ import { genFieldInfo, isNumericType } from "../../jacdac-spec/spectool/jdspec"
 import { RosServer } from "./rosserver"
 import { IndexedScreenServer } from "./indexedscreenserver"
 import { randomDeviceId } from "../jdom/random"
+import { SevenSegmentDisplayServer } from "./sevensegmentdisplayserver"
 
 const indoorThermometerOptions: AnalogSensorServerOptions = {
     readingValues: [21.5],
@@ -358,39 +359,17 @@ function initProviders() {
                 name: "7-segment (4 segments)",
                 serviceClasses: [SRV_SEVEN_SEGMENT_DISPLAY],
                 services: () => [
-                    new JDServiceServer(SRV_SEVEN_SEGMENT_DISPLAY, {
-                        intensityValues: [0xffff],
-                        valueValues: [fromHex("00000000")],
-                        registerValues: [
-                            {
-                                code: SevenSegmentDisplayReg.DigitCount,
-                                values: [4],
-                            },
-                            {
-                                code: SevenSegmentDisplayReg.DecimalPoint,
-                                values: [true],
-                            },
-                        ],
+                    new SevenSegmentDisplayServer({
+                        digits: fromHex("00000000"),
                     }),
                 ],
             },
             {
                 name: "7-segment (8 segments)",
                 serviceClasses: [SRV_SEVEN_SEGMENT_DISPLAY],
                 services: () => [
-                    new JDServiceServer(SRV_SEVEN_SEGMENT_DISPLAY, {
-                        intensityValues: [0xffff],
-                        valueValues: [fromHex("0000000000000000")],
-                        registerValues: [
-                            {
-                                code: SevenSegmentDisplayReg.DigitCount,
-                                values: [8],
-                            },
-                            {
-                                code: SevenSegmentDisplayReg.DecimalPoint,
-                                values: [true],
-                            },
-                        ],
+                    new SevenSegmentDisplayServer({
+                        digits: fromHex("0000000000000000"),
                     }),
                 ],
             },

src/servers/sevensegmentdisplayserver.ts

@@ -0,0 +1,52 @@
+import {
+    SRV_SEVEN_SEGMENT_DISPLAY,
+    SevenSegmentDisplayCmd,
+    SevenSegmentDisplayCmdPack,
+    SevenSegmentDisplayReg,
+} from "../jdom/constants"
+import { Packet } from "../jdom/packet"
+import { JDRegisterServer } from "../jdom/servers/registerserver"
+import { JDServiceServer } from "../jdom/servers/serviceserver"
+import { sevenSegmentDigitEncode } from "../jdom/sevensegment"
+
+export class SevenSegmentDisplayServer extends JDServiceServer {
+    readonly digits: JDRegisterServer<[Uint8Array]>
+    readonly digitCount: JDRegisterServer<[number]>
+    readonly decimalPoint: JDRegisterServer<[boolean]>
+    constructor(options: { digits: Uint8Array; decimalPoint?: boolean }) {
+        super(SRV_SEVEN_SEGMENT_DISPLAY, {
+            intensityValues: [0xffff],
+        })
+
+        const { digits, decimalPoint } = options
+
+        this.digitCount = this.addRegister<[number]>(
+            SevenSegmentDisplayReg.DigitCount,
+            [digits.length],
+        )
+        this.decimalPoint = this.addRegister<[boolean]>(
+            SevenSegmentDisplayReg.DecimalPoint,
+            [!!decimalPoint],
+        )
+        this.digits = this.addRegister<[Uint8Array]>(
+            SevenSegmentDisplayReg.Digits,
+            [digits],
+        )
+
+        this.addCommand(
+            SevenSegmentDisplayCmd.SetNumber,
+            this.handleSetNumber.bind(this),
+        )
+    }
+
+    private async handleSetNumber(pkt: Packet) {
+        const [digitCount] = this.digitCount.values()
+        const [value] = pkt.jdunpack<[number]>(
+            SevenSegmentDisplayCmdPack.SetNumber,
+        )
+        const digits = isNaN(value)
+            ? new Uint8Array(0)
+            : sevenSegmentDigitEncode(value, digitCount)
+        if (this.digits.setValues([digits])) await this.digits.sendGetAsync()
+    }
+}