Add 'clear screen' block to brick category (#100)

libs/core/_locales/core-jsdoc-strings.json

@@ -28,6 +28,7 @@
   "brick.buttonLeft": "Left button on the EV3 Brick.",
   "brick.buttonRight": "Right button on the EV3 Brick.",
   "brick.buttonUp": "Up button on the EV3 Brick.",
+  "brick.clearScreen": "Clears the screen",
   "brick.lightPattern": "Pattern block.",
   "brick.lightPattern|param|pattern": "the lights pattern to use. eg: LightsPattern.Green",
   "brick.print": "Show text on the screen.",

libs/core/_locales/core-strings.json

@@ -34,11 +34,12 @@
   "brick.buttonLeft|block": "left",
   "brick.buttonRight|block": "right",
   "brick.buttonUp|block": "up",
+  "brick.clearScreen|block": "`icons.brickDisplay` clear screen",
   "brick.lightPattern|block": "%pattern",
   "brick.print|block": "`icons.brickDisplay` print %text| at x: %x| y: %y",
   "brick.setPixel|block": "`icons.brickDisplay` set pixel %on| at x: %x| y: %y",
   "brick.setStatusLight|block": "set `icons.brickButtons` to %pattern=led_pattern",
-  "brick.showImage|block": "`icons.brickDisplay` show image %image=scren_image_picker",
+  "brick.showImage|block": "`icons.brickDisplay` show image %image=screen_image_picker",
   "brick|block": "brick",
   "control.raiseEvent|block": "raise event|from %src|with value %value",
   "control|block": "control",

libs/core/screen.ts

@@ -137,7 +137,7 @@ namespace brick {
      * Shows an image on screen
      * @param image image to draw
      */
-    //% blockId=screen_show_image block="`icons.brickDisplay` show image %image=scren_image_picker"
+    //% blockId=screen_show_image block="`icons.brickDisplay` show image %image=screen_image_picker"
     //% weight=95 group="Screen" blockGap=8
     export function showImage(image: Image, delay: number = 400) {
         if (!image) return;
@@ -151,7 +151,7 @@ namespace brick {
      * An image
      * @param image the image
      */
-    //% blockId=scren_image_picker block="%image" shim=TD_ID
+    //% blockId=screen_image_picker block="%image" shim=TD_ID
     //% image.fieldEditor="imagedropdown"
     //% image.fieldOptions.columns=6
     //% image.fieldOptions.hasSearchBar=true
@@ -160,6 +160,15 @@ namespace brick {
         return image;
     }
 
+    /**
+     * Clears the screen
+     */
+    //% blockId=screen_clear_screen block="`icons.brickDisplay` clear screen"
+    //% weight=94 group="Screen" blockGap=8
+    export function clearScreen() {
+        screen.clear();
+    }
+
     export function drawRect(x: number, y: number, w: number, h: number, mode = Draw.Normal) {
         x |= 0;
         y |= 0;

sim/state/screen.ts

@@ -30,6 +30,7 @@ namespace pxsim {
         clear() {
             for (let i = 0; i < this.points.length; ++i)
                 this.points[i] = 0;
+            this.shouldUpdate = true;
         }
 
         blitLineCore(x: number, y: number, w: number, buf: RefBuffer, mode: Draw, offset = 0) {