implement useSystemClipboard command (#665)

README.md

@@ -107,6 +107,14 @@ Put the following in your `settings.json`:
 
 and restart VSCode.
 
+#### How can I enable yanking to system clipboard by default?
+
+Put the following in your `settings.json`:
+
+```    "vim.useSystemClipboard": true```
+
+and restart VSCode.
+
 #### Vim option override sequence.
 
 The way we load Vim options is slightly different from native Vim as there is some overlap between Code and Vim. The option loading sequence is as below.

package.json

@@ -164,6 +164,11 @@
                     "type": "boolean",
                     "description": "Enable some vim ctrl key commands that override otherwise common operations, like ctrl+c"
                 },
+                "vim.useSystemClipboard": {
+                  "type": "boolean",
+                  "description": "Use system clipboard for unnamed register.",
+                  "default": false
+                },
                 "vim.insertModeKeyBindings": {
                     "type": "array",
                     "description": "Keybinding overrides to use for insert mode."

src/configuration/configuration.ts

@@ -50,6 +50,7 @@ export class Configuration {
   }
 
   useSolidBlockCursor: boolean = false;
+  useSystemClipboard: boolean = false;
   useCtrlKeys: boolean = false;
   scroll: number = 20;
   hlsearch: boolean = false;

src/mode/modeHandler.ts

@@ -138,8 +138,6 @@ export class VimState {
     return VisualBlockMode.getBottomRightPosition(this.cursorStartPosition, this.cursorPosition);
   }
 
-  public registerName = '"';
-
   /**
    * This is for oddball commands that don't manipulate text in any way.
    */
@@ -346,6 +344,11 @@ export class ReplaceState {
  *   * delete operator
  */
 export class RecordedState {
+
+  constructor() {
+    const useClipboard = Configuration.getInstance().useSystemClipboard;
+    this.registerName = useClipboard ? '*' : '"';
+  }
   /**
    * Keeps track of keys pressed for the next action. Comes in handy when parsing
    * multiple length movements, e.g. gg.
@@ -389,7 +392,7 @@ export class RecordedState {
   /**
    * The register name for this action.
    */
-  public registerName: string = '"';
+  public registerName: string;
 
   public clone(): RecordedState {
     const res = new RecordedState();