Fix #2050: add WIP visual mode

We need to make merging of nmaps happen at runtime
before we merge this, or we'll break the binds of
people who are just selecting text to help them
read.

src/content.ts

@@ -355,6 +355,15 @@ config.getAsync("leavegithubalone").then(v => {
     }
 })
 
+document.addEventListener("selectionchange", () => {
+    const selection = document.getSelection()
+    if (selection.anchorOffset == selection.focusOffset) {
+        contentState.mode = "normal"
+    } else {
+        contentState.mode = "visual"
+    }
+})
+
 // Listen for statistics from each content script and send them to the
 // background for collection. Attach the observer to the window object
 // since there's apparently a bug that causes performance observers to

src/content/controller_content.ts

@@ -101,6 +101,7 @@ function* ParserController() {
         ignore: keys => generic.parser("ignoremaps", keys),
         hint: hinting.parser,
         gobble: gobblemode.parser,
+        visual: keys => generic.parser("vmaps", keys),
     }
 
     while (true) {

src/content/state_content.ts

@@ -8,6 +8,7 @@ export type ModeName =
     | "ignore"
     | "gobble"
     | "input"
+    | "visual"
 
 export class PrevInput {
     inputId: string

src/lib/config.ts

@@ -302,6 +302,12 @@ export class default_config {
             "open https://www.youtube.com/watch?v=M3iOROuTuMA",
     }
 
+    vmaps = mergeDeep(this.nmaps, { // we really want a real-time merge as this means that user normal binds will no longer work while text is selected
+        "<Escape>": "composite js document.getSelection().empty(); mode normal; hidecmdline",
+        "<C-[>": "composite js document.getSelection().empty(); mode normal ; hidecmdline",
+        "y": "composite js document.getSelection().toString() | yank",
+    })
+
     hintmaps = {
         "<Backspace>": "hint.popKey",
         "<Escape>": "hint.reset",