From a1e1b484fc62bdc5ad0732d1f6cfef0837f5ca77 Mon Sep 17 00:00:00 2001
From: Andrew Morris <voltrevo@gmail.com>
Date: Sun, 5 Nov 2023 15:52:32 +1000
Subject: [PATCH] Use lines array, undefined means, stop, update example

---
 concept-code/console/ConsoleApp.ts |  2 +-
 concept-code/console/Counter.ts    | 39 +++++++++++++++++++++++-------
 vstc/src/console_command.rs        | 27 ++++++++++++++++++---
 3 files changed, 54 insertions(+), 14 deletions(-)

diff --git a/concept-code/console/ConsoleApp.ts b/concept-code/console/ConsoleApp.ts
index bc9c08f..091f111 100644
--- a/concept-code/console/ConsoleApp.ts
+++ b/concept-code/console/ConsoleApp.ts
@@ -9,7 +9,7 @@ type ConsoleApp<Db, View> = {
   render: (
     this: { db: Db; view: View },
     info: RenderInfo,
-  ) => string;
+  ) => string[] | undefined;
 
   onKeyDown: (this: { db: Db; view: View }, key: string) => void;
 };
diff --git a/concept-code/console/Counter.ts b/concept-code/console/Counter.ts
index 400737b..29ef98f 100644
--- a/concept-code/console/Counter.ts
+++ b/concept-code/console/Counter.ts
@@ -3,10 +3,9 @@ import type { RenderInfo } from "./ConsoleApp.ts";
 
 type View = {
   offset: number;
-};
+} | undefined;
 
-export default class ConsoleAppDemo
-  implements ConsoleApp<ConsoleAppDemo, View> {
+export default class Counter implements ConsoleApp<Counter, View> {
   value = 0;
 
   createView(): View {
@@ -14,18 +13,40 @@ export default class ConsoleAppDemo
   }
 
   render = function (
-    this: { db: ConsoleAppDemo; view: View },
+    this: { db: Counter; view: View },
     { screenWidth, screenHeight }: RenderInfo,
   ) {
-    return `${
-      " ".repeat(this.view.offset)
-    }${this.db.value}\n${screenWidth}x${screenHeight}`;
+    if (this.view === undefined) {
+      return undefined;
+    }
+
+    let wCenter = Math.floor(screenWidth / 2);
+    let hCenter = Math.floor(screenHeight / 2);
+
+    let lines = [];
+
+    for (let i = 0; i < hCenter; i++) {
+      lines.push("");
+    }
+
+    lines.push(" ".repeat(wCenter + this.view.offset) + this.db.value);
+
+    return lines;
   };
 
-  onKeyDown = function (this: { db: ConsoleAppDemo; view: View }, key: string) {
+  onKeyDown = function (this: { db: Counter; view: View }, key: string) {
+    if (this.view === undefined) {
+      return;
+    }
+
     switch (key) {
+      case "q": {
+        this.view = undefined;
+        break;
+      }
+
       case "ArrowLeft": {
-        this.view.offset = Math.max(0, this.view.offset - 1);
+        this.view.offset--;
         break;
       }
 
diff --git a/vstc/src/console_command.rs b/vstc/src/console_command.rs
index bb504ca..f63de4b 100644
--- a/vstc/src/console_command.rs
+++ b/vstc/src/console_command.rs
@@ -141,6 +141,7 @@ impl ConsoleApp {
             Key::Right => "ArrowRight".to_string(),
             Key::Up => "ArrowUp".to_string(),
             Key::Down => "ArrowDown".to_string(),
+            Key::Char(c) => c.to_string(),
             _ => continue,
           };
 
@@ -200,20 +201,38 @@ impl ConsoleApp {
       .run(None, &mut self.ctx, render, vec![info])
       .or_exit_uncaught()
     {
-      Val::String(s) => {
+      Val::Array(arr) => {
         write!(
           self.stdout,
-          "{}{}{}",
+          "{}{}",
           termion::clear::All,
           termion::cursor::Goto(1, 1),
-          s
         )
         .unwrap();
 
+        for (i, line) in arr.elements.iter().enumerate() {
+          match line {
+            Val::String(s) => {
+              write!(
+                self.stdout,
+                "{}{}",
+                termion::cursor::Goto(1, (i as u16) + 1),
+                s
+              )
+              .unwrap();
+            }
+            line => {
+              println!("ERROR: Non-string line: {}", line.pretty());
+              exit(1);
+            }
+          }
+        }
+
         self.stdout.flush().unwrap();
       }
+      Val::Undefined => exit(0),
       non_str => {
-        println!("ERROR: Non-string render: {}", non_str.pretty());
+        println!("ERROR: Non-array render: {}", non_str.pretty());
         exit(1);
       }
     }