Erase on showstring + showports improvements (#402)

* erase line before show string + show ports upgrade

* fixed font size

* fixing console output

docs/examples/print-ports.md

@@ -1,40 +0,0 @@
-
-# Print Ports
-
-```typescript
-/**
- * Print the port states on the screen
- */
-//% blockId=brickPrintPorts block="print ports"
-//% help=brick/print-ports
-//% weight=1 group="Screen"
-function printPorts() {
-    const col = 44;
-    clearScreen();
-
-    function scale(x: number) {
-        if (Math.abs(x) > 1000) return Math.round(x / 100) / 10 + "k";
-        return ("" + (x >> 0));
-    }
-
-    // motors
-    const datas = motors.getAllMotorData();
-    for(let i = 0; i < datas.length; ++i) {
-        const data = datas[i];
-        if (!data.actualSpeed && !data.count) continue;
-        const x = i * col;
-        print(`${scale(data.actualSpeed)}%`, x, brick.LINE_HEIGHT)
-        print(`${scale(data.count)}>`, x, 2 * brick.LINE_HEIGHT)
-        print(`${scale(data.tachoCount)}|`, x, 3 * brick.LINE_HEIGHT)
-    }
-
-    // sensors
-    const sis = sensors.internal.getActiveSensors();
-    for(let i =0; i < sis.length; ++i) {
-        const si = sis[i];
-        const x = (si.port() - 1) * col;
-        const v = si._query();
-        print(`${scale(v)}`, x, 9 * brick.LINE_HEIGHT)
-    }
-}
-```

libs/core/console.ts

@@ -59,7 +59,6 @@ namespace console {
 
 namespace console._screen {
     const maxLines = 100;
-    const screenLines = 10;
     let lines: string[];
     let scrollPosition = 0;
 
@@ -75,10 +74,11 @@ namespace console._screen {
     function printLog() {
         brick.clearScreen()
         if (!lines) return;
+        const screenLines = brick.lineCount();
         for (let i = 0; i < screenLines; ++i) {
             const line = lines[i + scrollPosition];
             if (line)
-                screen.print(line, 0, 4 + i * brick.LINE_HEIGHT)
+                screen.print(line, 0, 4 + i * brick.lineHeight(), 1, brick.font)
         }
     }
 
@@ -98,6 +98,7 @@ namespace console._screen {
             scrollPosition = Math.min(scrollPosition, lines.length - 1)
         }
         // move down scroll once it gets large than the screen
+        const screenLines = brick.lineCount();
         if (lines.length > screenLines
             && lines.length >= scrollPosition + screenLines) {
             scrollPosition++;

libs/screen/targetoverrides.ts

@@ -20,22 +20,45 @@ namespace _screen_internal {
 }
 
 namespace brick {
-    export const LINE_HEIGHT = 12;
+    const textOffset = 4;
+    const lineOffset = 2;
+    export let font = image.font8;
+
+    /**
+     * Gets the text line height
+     */
+    //%
+    export function lineHeight(): number {
+        return font.charHeight + lineOffset;
+    }
+
+    /**
+     * Number of lines
+     */
+    //%
+    export function lineCount(): number {
+        return ((screen.height - textOffset) / lineHeight()) >> 0
+    }
 
     /**
      * Show text on the screen at a specific line.
      * @param text the text to print on the screen, eg: "Hello world"
-     * @param line the line number to print the text at, eg: 1
+     * @param line the line number to print the text at (starting at 1), eg: 1
      */
     //% blockId=screen_print block="show string %text|at line %line"
     //% weight=98 group="Screen" inlineInputMode="inline" blockGap=8
     //% help=brick/show-string
     //% line.min=1 line.max=10
     export function showString(text: string, line: number) {
-        const NUM_LINES = 9;
+        // line indexing starts at 1.
-        const offset = 5;
+        line = (line - 1) >> 0;
-        const y = offset + (Math.clamp(0, NUM_LINES, line - 1) / (NUM_LINES + 2)) * DAL.LCD_HEIGHT;
+        const nlines = lineCount();
-        screen.print(text, offset, y);
+        if (line < 0 || line > nlines) return; // out of screen
+
+        const h = lineHeight();
+        const y = textOffset + h * line;
+        screen.fillRect(0, y, screen.width, h, 0); // clear background
+        screen.print(text, textOffset, y, 1, font);
     }
 
     /**
@@ -85,6 +108,7 @@ namespace brick {
     //% weight=10 group="Screen"
     export function showPorts() {
         const col = 44;
+        const lineHeight8 = image.font8.charHeight + 2;
         clearScreen();
 
         function scale(x: number) {
@@ -98,19 +122,22 @@ namespace brick {
             const data = datas[i];
             if (!data.actualSpeed && !data.count) continue;
             const x = i * col;
-            screen.print("ABCD"[i], x, brick.LINE_HEIGHT)
+            screen.print("ABCD"[i], x + 2, 1 * lineHeight8, 1, image.font8)
-            screen.print(`${scale(data.actualSpeed)}%`, x, 2* brick.LINE_HEIGHT)
+            screen.print(`${scale(data.actualSpeed)}%`, x + 2, 3 * lineHeight8, 1, image.font8)
-            screen.print(`${scale(data.count)}>`, x, 3 * brick.LINE_HEIGHT)
+            screen.print(`${scale(data.count)}>`, x + 2, 4 * lineHeight8, 1, image.font5)
         }
+        screen.drawLine(0, 5 * lineHeight8, screen.width, 5 * lineHeight8, 1);
 
         // sensors
         const sis = sensors.internal.getActiveSensors();
+        const h = screen.height;
+        screen.drawLine(0, h - 5 * lineHeight8, screen.width, h - 5 * lineHeight8, 1)
         for (let i = 0; i < sis.length; ++i) {
             const si = sis[i];
             const x = (si.port() - 1) * col;
             const inf = si._info();
-            screen.print(si.port() + "", x, 8 * brick.LINE_HEIGHT)
+            screen.print(si.port() + "", x, h - 4 * lineHeight8, 1, image.font8)
-            screen.print(inf, x, 9 * brick.LINE_HEIGHT)
+            screen.print(inf, x, h - 2 * lineHeight8, 1, inf.length > 4 ? image.font5 : image.font8);
         }
     }