Added clear command and api

Author: PROPHESSOR

js/core/stdio/default.js

@@ -23,6 +23,8 @@ let bgcolor = tty.color.BLACK;
 
 defaultStdio.onwrite = text => tty.print(text, 1, fgcolor, bgcolor);
 
+defaultStdio.onclear = tty.clear;
+
 defaultStdio.onsetcolor = (fg) => {
   if (!fg) {
     fgcolor = tty.color.WHITE;

js/core/stdio/interface.js

@@ -41,6 +41,10 @@ class StdioInterface {
     this.onsetbackgroundcolor(bg);
   }
 
+  clear() {
+    this.onclear();
+  }
+
   // stdin
   read(cb) {
     this.onread(cb);

js/core/tty/index.js

@@ -14,7 +14,6 @@
 
 'use strict';
 
-/* eslint-disable quotes */
 const terminal = require('./terminal');
 const { DARKGRAY, BLACK, YELLOW, GREEN, LIGHTGRAY } = terminal.color;
 
@@ -33,6 +32,6 @@ terminal.print('\n Welcome to ', 1, DARKGRAY, BLACK);
 terminal.print('JsOS\n', 1, GREEN, BLACK);
 terminal.print('Type', 1, LIGHTGRAY, BLACK);
 terminal.print(' help ', 1, YELLOW, BLACK);
-terminal.print('to get commands\n\n', 1, LIGHTGRAY, BLACK);
+terminal.print('to get list of commands\n\n', 1, LIGHTGRAY, BLACK);
 
 module.exports = terminal;

js/core/tty/printer.js

@@ -30,6 +30,17 @@ function scrollUp() {
   posCurrent -= w;
 }
 
+function scrollDown() {
+  buffer.scrollDown(vga.color.BLACK);
+  posCurrent -= w;
+}
+
+function clear() {
+  buffer.clear(vga.color.BLACK);
+  posCurrent = 0;
+  refresh();
+}
+
 refresh();
 
 exports.color = vga.color;
@@ -88,3 +99,7 @@ exports.moveTo = (xOpt, yOpt) => {
   }
   posCurrent = (y * w) + x;
 };
+
+exports.scrollUp = scrollUp;
+exports.scrollDown = scrollDown;
+exports.clear = clear;

js/core/tty/terminal.js

@@ -21,6 +21,7 @@ exports.color = printer.color;
 exports.print = printer.print;
 exports.moveOffset = printer.moveOffset;
 exports.moveTo = printer.moveTo;
+exports.clear = printer.clear;
 
 let isReading = false;
 
@@ -84,6 +85,12 @@ exports.readLine = (cb) => {
       case 'kpend':
         editor.moveCursorEnd();
         break;
+      case 'kppageup':
+        printer.scrollUp(0);
+        break;
+      case 'kppagedown':
+        printer.scrollDown(0);
+        break;
       case 'character':
         editor.putChar(keyinfo.character);
         break;

js/core/tty/vga.js

@@ -113,6 +113,15 @@ class VGABuffer {
       setCharXY(this.b, t, h - 1, ' ', bg, bg);
     }
   }
+  scrollDown(bg) {
+    // testInstance(this);
+    // testColor(bg);
+    // this.b.set(this.b.subarray(w * 2, w * h * 2));
+    // for (let t = 0; t < w; ++t) {
+    //   setCharXY(this.b, t, h + 1, ' ', bg, bg);
+    // }
+    return debug('Not implented!');
+  }
 }
 
 function testInstance(obj) {

js/service/shell/commands.js

@@ -46,6 +46,14 @@ const cmds = {
       return res(0);
     },
   },
+  clear: {
+    description: 'Clear the display',
+    usage: 'clear',
+    run(a, f, res) {
+      f.stdio.clear();
+      return res(0);
+    },
+  },
   help: {
     description: 'Show this message or show usage of the command =)',
     usage: 'help <command>',