More command binding

Now can bind editable commands with `command-edit:`

Ref #974

cmd/micro/bindings.go

@@ -479,6 +479,9 @@ func BindKey(k, v string) {
 		} else if strings.HasPrefix(actionName, "command:") {
 			cmd := strings.SplitN(actionName, ":", 2)[1]
 			actions = append(actions, CommandAction(cmd))
+		} else if strings.HasPrefix(actionName, "command-edit:") {
+			cmd := strings.SplitN(actionName, ":", 2)[1]
+			actions = append(actions, CommandEditAction(cmd))
 		} else {
 			actions = append(actions, findAction(actionName))
 		}

cmd/micro/command.go

@@ -120,6 +120,16 @@ func DefaultCommands() map[string]StrCommand {
 	}
 }
 
+func CommandEditAction(prompt string) func(*View, bool) bool {
+	return func(v *View, usePlugin bool) bool {
+		input, canceled := messenger.Prompt("> ", prompt, "Command", CommandCompletion)
+		if !canceled {
+			HandleCommand(input)
+		}
+		return false
+	}
+}
+
 func CommandAction(cmd string) func(*View, bool) bool {
 	return func(v *View, usePlugin bool) bool {
 		HandleCommand(cmd)

runtime/help/keybindings.md

@@ -47,6 +47,33 @@ save and quit you can bind it like so:
 }
 ```
 
+## Binding commands
+
+You can also bind a key to execute a command in command mode (see 
+`help commands`). Simply prepend the binding with `command:`. For example:
+
+```json
+{
+    "Alt-p": "command:pwd"
+}
+```
+
+Now when you press `Alt-p` the `pwd` command will be executed which will show
+your working directory in the infobar.
+
+You can also bind an "editable" command with `command-edit:`. This means that 
+micro won't immediately execute the command when you press the binding, but
+instead just place the string in the infobar in command mode. For example, 
+you could rebind `CtrlG` to `> help`:
+
+```json
+{
+    "CtrlG": "command-edit:help "
+}
+```
+
+Now when you press `CtrlG`, `help` will appear in the command bar and your cursor will
+be placed after it (note the space in the json that controls the cursor placement).
 
 ## Binding raw escape sequences