synthing

commit 1d93dc71393cf34079292d22b1db2005eac372ea
parent 87c151a4227bc3d4f090b7e7a29d430cb5288f66
Author: Massimo Siboldi <mdsiboldi@gmail.com>
Date:   Sun, 10 Dec 2017 18:43:43 -0800

Add throttle to wave editor

Diffstat:
M
src/WaveEditor/index.js
 | 
5
++---
M
src/helpers.js
 | 
11
++++++++++-

2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/src/WaveEditor/index.js b/src/WaveEditor/index.js
@@ -2,7 +2,7 @@ import { h, Component } from 'preact';
 import consts from '../consts.js';
 import helpers from '../helpers.js';
 
-const drawArea = (amplitudes, canvas, begin = 0, end = undefined) => {
+const drawArea = helpers.throttle((amplitudes, canvas, begin = 0, end = undefined) => {
     const ctx = canvas.getContext("2d");
     const rectWidth = canvas.width / consts.BUF_SIZE;
     const roundedWidth = Math.max(1, rectWidth)
@@ -19,7 +19,7 @@ const drawArea = (amplitudes, canvas, begin = 0, end = undefined) => {
             ctx.fillRect(roundedXOffset, -amp + halfCanvas, roundedWidth + 1, lineWidth);
         });
     });
-}
+}, 20)
 
 const smoothZoneRange = function (waveData, begin, end) {
     if (begin > end) {
@@ -38,7 +38,6 @@ export default class waveEditor extends Component {
     componentDidMount() {
         drawArea(this.props.waveform, this.canvasRef);
         const handleMove = (ev) => {
-            console.log('handling move');
             this.updateWaveform({
                 x: ev.x + window.scrollX,
                 y: ev.y + window.scrollY
diff --git a/src/helpers.js b/src/helpers.js
@@ -9,6 +9,15 @@ export default {
             handler(ev);
         }
         target.addEventListener(type, doOnce);
+    },
+    throttle: (fn, ms) => {
+        let time = 0;
+        return (...args) => {
+            let now = Date.now();
+            if (now >= time + ms) {
+                fn(...args);
+                time = now;
+            }
+        }
     }
-
 };