a mini-console support with scroll up / down (#112)

* a mini-console support with scroll up / down

* fix compile error

libs/base/_locales/base-jsdoc-strings.json

@@ -123,11 +123,6 @@
   "String.substr": "Return a substring of the current string.",
   "String.substr|param|length": "number of characters to extract",
   "String.substr|param|start": "first character index; can be negative from counting from the end, eg:0",
-  "console": "Reading and writing data to the console output.",
-  "console.log": "Write a line of text to the console output.",
-  "console.logValue": "Write a name:value pair as a line of text to the console output.",
-  "console.logValue|param|name": "name of the value stream, eg: \"x\"",
-  "console.logValue|param|value": "to write",
   "control": "Program controls and events.",
   "control.AnimationQueue.cancel": "Cancels the current running animation and clears the queue",
   "control.AnimationQueue.runUntilDone": "Runs 'render' in a loop until it returns false or the 'stop' function is called",

libs/base/_locales/base-strings.json

@@ -19,9 +19,6 @@
   "String.length|block": "length of %VALUE",
   "String.substr|block": "substring of %this=text|from %start|of length %length",
   "String|block": "String",
-  "console.logValue|block": "console|log value %name|= %value",
-  "console.log|block": "console|log %text",
-  "console|block": "console",
   "control.assert|block": "assert %cond|with value %code",
   "control.deviceSerialNumber|block": "device serial number",
   "control.millis|block": "millis (ms)",
@@ -46,7 +43,6 @@
   "{id:category}Arrays": "Arrays",
   "{id:category}Boolean": "Boolean",
   "{id:category}Buffer": "Buffer",
-  "{id:category}Console": "Console",
   "{id:category}Control": "Control",
   "{id:category}Helpers": "Helpers",
   "{id:category}Loops": "Loops",

libs/base/pxt.json

@@ -17,8 +17,7 @@
         "control.cpp",
         "control.ts",
         "serial.cpp",
-        "serial.ts",
-        "console.ts"
+        "serial.ts"
     ],
     "testFiles": [
         "test.ts"

libs/core/_locales/core-jsdoc-strings.json

@@ -43,6 +43,13 @@
   "brick.setStatusLight|param|pattern": "the lights pattern to use.",
   "brick.showImage": "Shows an image on screen",
   "brick.showImage|param|image": "image to draw",
+  "console": "Reading and writing data to the console output.\r\n\r\nReading and writing data to the console output.",
+  "console.addListener": "Adds a listener for the log messages",
+  "console.log": "Write a line of text to the console output.",
+  "console.logValue": "Write a name:value pair as a line of text to the console output.",
+  "console.logValue|param|name": "name of the value stream, eg: \"x\"",
+  "console.logValue|param|value": "to write",
+  "console.sendToScreen": "Sends the log messages to the brick screen and uses the brick up and down buttons to scroll.",
   "control": "Program controls and events.",
   "control.allocateNotifyEvent": "Allocates the next user notification event",
   "control.deviceFirmwareVersion": "Determine the version of system software currently running.",

libs/core/_locales/core-strings.json

@@ -41,6 +41,10 @@
   "brick.setStatusLight|block": "set `icons.brickButtons` to %pattern=led_pattern",
   "brick.showImage|block": "`icons.brickDisplay` show image %image=screen_image_picker",
   "brick|block": "brick",
+  "console.logValue|block": "console|log value %name|= %value",
+  "console.log|block": "console|log %text",
+  "console.sendToScreen|block": "send console to screen",
+  "console|block": "console",
   "control.raiseEvent|block": "raise event|from %src|with value %value",
   "control|block": "control",
   "motors.Motor.move|block": "move `icons.motorLarge` %motor|for %value|%unit|at %speed|%",
@@ -71,6 +75,7 @@
   "sensors|block": "sensors",
   "serial|block": "serial",
   "{id:category}Brick": "Brick",
+  "{id:category}Console": "Console",
   "{id:category}Control": "Control",
   "{id:category}Image": "Image",
   "{id:category}Images": "Images",

libs/core/console.ts

@@ -0,0 +1,107 @@
+/// <reference no-default-lib="true"/>
+
+/**
+ * Reading and writing data to the console output.
+ */
+//% weight=12 color=#002050 icon="\uf120"
+//% advanced=true
+namespace console {
+    type Listener = (text: string) => void;
+
+    const listeners: Listener[] = [
+        (text: string) => serial.writeLine(text)
+    ];
+
+    /**
+     * Write a line of text to the console output.
+     * @param value to send
+     */
+    //% weight=90
+    //% help=console/log blockGap=8
+    //% blockId=console_log block="console|log %text"
+    export function log(text: string): void {
+        for (let i = 0; i < listeners.length; ++i)
+            listeners[i](text);
+    }
+
+    /**
+     * Write a name:value pair as a line of text to the console output.
+     * @param name name of the value stream, eg: "x"
+     * @param value to write
+     */
+    //% weight=88 blockGap=8
+    //% help=console/log-value
+    //% blockId=console_log_value block="console|log value %name|= %value"
+    export function logValue(name: string, value: number): void {
+        log(`${name}: ${value}`)
+    }
+
+    /**
+     * Adds a listener for the log messages
+     * @param listener 
+     */
+    //%
+    export function addListener(listener: (text: string) => void) {
+        if (!listener) return;
+        listeners.push(listener);
+    }
+
+    /**
+     * Sends the log messages to the brick screen and uses the brick up and down buttons to scroll.
+     */
+    //% blockId=logsendtostreen block="send console to screen"
+    //% weight=1
+    export function sendToScreen(): void {
+        console.screen.attach();
+    }
+}
+
+namespace console.screen {
+    const maxLines = 100;
+    const screenLines = 8;
+    const lineHeight = 12;
+    let lines: string[];
+    let scrollPosition = 0;
+
+    export function attach() {
+        if (!lines) {
+            lines = [];
+            console.addListener(log);
+            brick.buttonUp.onEvent(ButtonEvent.Click, () => scroll(1))
+            brick.buttonDown.onEvent(ButtonEvent.Click, () => scroll(-1))                
+        }
+    }
+
+    function printLog() {
+        brick.clearScreen()
+        if (!lines) return;
+        for (let i = 0; i < screenLines; ++i) {
+            const line = lines[i + scrollPosition];
+            if (line)
+                brick.print(line, 0, 4 + i * lineHeight)
+        }
+    }
+
+    function scroll(pos: number) {
+        if (!pos) return;
+
+        scrollPosition += pos >> 0;
+        if (scrollPosition >= lines.length) scrollPosition = lines.length - 1;
+        if (scrollPosition < 0) scrollPosition = 0;
+        printLog();
+    }
+
+    function log(msg: string): void {    
+        lines.push(msg);
+        if (lines.length + 5 > maxLines) {
+            lines.splice(0, maxLines - lines.length);
+            scrollPosition = Math.min(scrollPosition, lines.length - 1)
+        }
+        // move down scroll once it gets large than the screen
+        if (lines.length > screenLines
+            && lines.length >= scrollPosition + screenLines) {
+            scrollPosition++;
+        }
+        printLog();
+    }
+}

libs/core/pxt.json

@@ -10,6 +10,7 @@
         "linux.cpp",
         "mmap.cpp",
         "control.cpp",
+        "console.ts",
         "serialnumber.cpp",
         "buttons.ts",
         "png.cpp",