diff --git a/desktop/sources/scripts/commander.js b/desktop/sources/scripts/commander.js
index 2914037..93c2b23 100644
--- a/desktop/sources/scripts/commander.js
+++ b/desktop/sources/scripts/commander.js
@@ -130,6 +130,8 @@ function Commander (ronin) {
     this._input.value = this._input.value.replace('$path', `"${path}"`)
   }
 
+  // Helpers
+
   this.commit = function (shape, end = false, run = false) {
     if (this.cache.indexOf('$') < 0) { return }
     const segs = this.cache.split('$')
@@ -151,6 +153,9 @@ function Commander (ronin) {
     } else if (word.substr(0, 4) === 'drag' && shape.line) {
       const rect = shape.rect
       this._input.value = this.cache.replace('$drag', `(drag (rect ${rect.x} ${rect.y} ${rect.w} ${rect.h}) $line)`)
+    } else if (word.substr(0, 4) === 'view' && shape.line) {
+      const rect = shape.rect
+      this._input.value = this.cache.replace('$view', `(view (rect ${rect.x} ${rect.y} ${rect.w} ${rect.h}) $rect)`)
     }
     if (end === true) {
       this.cache = this._input.value
diff --git a/desktop/sources/scripts/library.js b/desktop/sources/scripts/library.js
index 4997969..0d7c418 100644
--- a/desktop/sources/scripts/library.js
+++ b/desktop/sources/scripts/library.js
@@ -155,7 +155,7 @@ function Library (ronin) {
     return [a, b]
   }
 
-  this.drag = (rect = this.frame(), line = this.line()) => {
+  this.drag = (rect = this.frame(), line = this.line()) => { // Drag a part of the canvas.
     const pos = { x: line.b.x - line.a.x, y: line.b.y - line.a.y }
     const crop = ronin.surface.getCrop(rect)
     ronin.surface.clear(rect)
@@ -165,6 +165,13 @@ function Library (ronin) {
     ronin.surface.context.drawImage(crop, rect.x, rect.y)
   }
 
+  this.view = (a, b) => { // View a part of the canvas.
+    this.guide({ a: { x: a.x, y: a.y }, b: { x: b.x, y: b.y } })
+    this.guide(a)
+    this.guide(b)
+    ronin.surface.context.drawImage(ronin.surface.getCrop(a), b.x, b.y, b.w, b.h)
+  }
+
   this.theme = (variable, el = document.documentElement) => {
     // ex. (theme "f_main") -> :root { --f_main: "#fff" }
     return getComputedStyle(el).getPropertyValue(`--${variable}`)