improved terminal with history

src/bin/Terminal.hx

@@ -1,6 +1,5 @@
 package bin;
 
-import kernel.log.Log;
 import kernel.binstore.BinStore;
 import kernel.ps.ProcessHandle;
 import kernel.ps.Process;
@@ -11,11 +10,18 @@ import kernel.ui.WindowContext;
 using tink.CoreApi;
 
 class Terminal implements Process {
-	private var context:WindowContext;
+	private static inline final MAX_BACKLOG:Int = 100;
+
+	private var handle:ProcessHandle;
+
+	private var ctx:WindowContext;
+	private var requestRender: () -> Void;
+	
 	private var input:String = "";
 	private var backlog:Array<String> = [];
-	private var handle:ProcessHandle;
+	private var history:Array<String> = [];
-	private var requestRender: () -> Void;
+	private var historyIndex:Int = 0;
+
 	private var runningPID:PID = -1; 
 
 	public function new() {}
@@ -25,18 +31,20 @@ class Terminal implements Process {
 
 		var statelessContext = handle.createStatelessWindowContext();
 
-		this.context = statelessContext.ctx;
+		this.ctx = statelessContext.ctx;
 		this.requestRender = statelessContext.requestRender;
 
 		statelessContext.setRenderFunc(this.render);
 
-		handle.addCallbackLink(this.context.onChar.handle(char -> {
+		// Add input event handlers
+		handle.addCallbackLink(this.ctx.onChar.handle(char -> {
 			if (this.runningPID > 0) return;
 			this.input += char;
 			this.requestRender();
 		}));
 
-		handle.addCallbackLink(this.context.onKey.handle(e -> {
+		// Add key event handlers
+		handle.addCallbackLink(this.ctx.onKey.handle(e -> {
 			switch (e.keyCode) {
 				case 259: // Backspace
 					if (this.runningPID > 0) return;
@@ -48,9 +56,16 @@ class Terminal implements Process {
 					var command = this.input;
 					this.input = "";
 					this.requestRender();
+					this.historyIndex = 0;
 					this.invokeCommand(command);
 				case 269: // END
 					this.stopCurrentPS();
+				case 265: // UP
+					if (this.historyIndex < this.history.length) {
+						this.historyIndex++;
+						this.input = this.history[this.history.length - this.historyIndex];
+						this.requestRender();
+					}
 			}
 		}));
 
@@ -66,12 +81,7 @@ class Terminal implements Process {
 	}
 
 	private function render() {
-		redrawBacklog();
+		var size = this.ctx.getSize();
-		redrawInput();
-	}
-
-	private function redrawBacklog() {
-		var size = this.context.getSize();
 		var linesAvailable = size.y - 1;
 
 		var start:Int = this.backlog.length - linesAvailable;
@@ -79,29 +89,28 @@ class Terminal implements Process {
 		for (i in 0...linesAvailable) {
 			var line = this.backlog[start + i];
 
-			this.context.setCursorPos(0, i);
+			this.ctx.setCursorPos(0, i);
-			this.context.clearLine();
+			this.ctx.clearLine();
 
 			if (line != null) {
-				this.context.write(line);
+				this.ctx.write(line);
 			}
 		}
-		this.moveCursorToInput();
+
+		this.ctx.setCursorPos(0, size.y - 1);
+		this.ctx.clearLine();
+
+		this.ctx.setTextColor(Color.Blue);
+		this.ctx.write("> ");
+
+		this.ctx.setTextColor(Color.White);
+		this.ctx.write(this.input);
+
+		if (this.runningPID < 0) {
+			this.ctx.setCursorBlink(true);
+		} else {
+			this.ctx.setCursorBlink(false);
 		}
-
-	private function redrawInput() {
-		var size = this.context.getSize();
-
-		this.context.setCursorPos(0, size.y - 1);
-		this.context.clearLine();
-
-		this.context.setTextColor(Color.Blue);
-		this.context.write("> ");
-
-		this.context.setTextColor(Color.White);
-		this.context.write(this.input);
-
-		this.context.setCursorBlink(true);
 	}
 
 	private function invokeCommand(command:String):Void {
@@ -110,6 +119,13 @@ class Terminal implements Process {
 		if (args.length == 0) {
 			return;
 		}
+
+		this.history.push(command);
+
+		if (this.history.length > MAX_BACKLOG) {
+			this.history.shift();
+		}
+
 		var commandName = args[0];
 
 		// Handle built-in commands
@@ -125,8 +141,7 @@ class Terminal implements Process {
 		var ps = getProgByName(commandName);
 		if (ps == null) {
 			this.backlog.push("Unknown command: " + commandName);
-			this.redrawBacklog();
+			this.requestRender();
-			this.redrawInput();
 			return;
 		}
 
@@ -149,6 +164,11 @@ class Terminal implements Process {
 					} else {
 						this.backlog[this.backlog.length - 1] += s;
 					}
+
+					// Trim the backlog if it's too long
+					if (this.backlog.length > MAX_BACKLOG) {
+						this.backlog.shift();
+					}
 				}
 				
 				this.requestRender();
@@ -163,9 +183,12 @@ class Terminal implements Process {
 			}
 		});
 
-		this.context.setCursorBlink(false);
+		this.ctx.setCursorBlink(false);
 	}
 
+	/**
+		Convter a command string into an array of arguments where the first element is the command name
+	**/
 	private function parseArgs(command:String):Array<String> {
 		// TODO: tim and quote handling
 		return command.split(" ");
@@ -173,7 +196,7 @@ class Terminal implements Process {
 
 	private function clear() {
 		this.backlog = [];
-		this.redrawBacklog();
+		this.requestRender();
 	}
 
 	private function getProgByName(name:String):Process {
@@ -186,7 +209,7 @@ class Terminal implements Process {
 	}
 
 	private function moveCursorToInput() {
-		var size = this.context.getSize();
+		var size = this.ctx.getSize();
-		this.context.setCursorPos(this.input.length + 2, size.y - 1);
+		this.ctx.setCursorPos(this.input.length + 2, size.y - 1);
 	}
 }