@flyskywhy/react-native-gcanvas/docs/Guide_iOS_Setup_Weex.md

A C++ native canvas 2D/WebGL component based on gpu opengl glsl shader GCanvas

# GCanvas Weex Bridge iOS Guide

If your project use Weex, and want to integrate GCanvas, or you want to see how to run Weex sample with GCanvas. This guide is just for you.

## Integrate GCanvas

#### Requirement

* Make sure that you have installed the [iOS development environment](https://help.apple.com/xcode/mac/current/#/dev60b6fbbc7) and [CocoaPods](https://guides.cocoapods.org/using/getting-started.html).
* Make sure that you have integrate [WeexSDK](https://github.com/apache/incubator-weex#ios)  >= 0.16.X
* Make sure that you have insalled the [weex-toolkit](https://www.npmjs.com/package/weex-toolkit) in [Nodejs](https://nodejs.org/en/) 4.0+ for running case

#### Installation with CocoaPods

Add these pods to your Podfile and run `pod install` to install:

```objective-c
pod 'WeexGcanvas'
pod 'WeexPluginLoader'
```

`WeexPluginLoader` would dynamic register Weex `Module` and `Component` of GCanvas, so we do not need to register manually. dd

Now, you can use official sample  to test GCanvas, `sample.vue` file in path `./examples/2d/sammple.vue`. 

You can also write a sample by youself. 


## Write Weex Sample
Before write a Weex sample,  you should learn [Weex Tutorial](http://weex.apache.org/guide/#overview).

There is a  simple page below,  find this in path `./bridges/weex-bridge/examples/2d/simple.vue`. 
```javascript
<template>
	<div ref="test">
		<gcanvas ref="canvas_holder" style="width:750;height:750;background-color:rgba(0,0,0,0.1)"></gcanvas>
	</div>
</template>
<script>

//for debug
const enable = require('../../../../js/dist/gcanvas.min.js').enable;
const WeexBridge = require('../../../../js/dist/gcanvas.min.js').WeexBridge;
const GImage = require('../../../../js/dist/gcanvas.min.js').Image;

	
module.exports = {
    mounted: function () {
        var ref = this.$refs.canvas_holder;
        var size = {width:750, height:750};
        var gcanvas = enable(ref, size);
        var ctx = gcanvas.getContext('2d');

        //rect
        ctx.fillStyle = 'red';
        ctx.fillRect(0, 0, 100, 100);

        //rect
        ctx.fillStyle = 'black';
        ctx.fillRect(100, 100, 100, 100);
        ctx.fillRect(25, 210, 700, 5);

        //circle
        ctx.arc(450, 200, 100, 0, Math.PI * 2, true);
        ctx.fill();

		//image
        var image = new GImage();
        image.src = 'https://gw.alicdn.com/tfs/TB1KwRTlh6I8KJjy0FgXXXXzVXa-225-75.png';
        image.onload = function(){
          ctx.drawImage(image, 100, 300);
        };
    }
};
</script>
```


## Run Weex Sample

* **Fisrt**,  Use `weex-toolkit`to create Weex Javascript bundle.  
  ```shell
  weex preview sample.vue
  ```
  There would be lanuch a default browser(Chrome) , and generate Javascript bundle show as qrcode.

* **Second**,Install `GCanvasPlayground` app
  run `pod install` in `ios/playground` path, and then install `GCanvasPlayground` app on your iPhone device. 

* **Finally**, Run `GCanvasPlayground` app, scan qrcode created at first setp. If you get reuslt same as below, congratuation. 
	<img src='https://img.alicdn.com/tfs/TB1z9ijX29TBuNjy0FcXXbeiFXa-1242-2208.png' width="60%">