我如何制作一个看起来像切换的浏览器操作按钮

时间：2016-11-15 06:45:37

标签： javascript firefox firefox-addon firefox-webextensions

目标是获取Firefox的WebExtension，可以由工具栏中的用户激活/停用，例如开/关开关。

我在这段代码中使用 background.js ：

browser.browserAction.onClicked.addListener(function (tab) {
    switch (button) {
        case 'turn-on':
            enable();
            break;
        case 'turn-off':
            disable();
            break;
    }
});
function enable() {
    browser.browserAction.setIcon({ path: '/ui/is-on.png', });
    browser.browserAction.setPopup({ popup: '/ui/turn-off.js', });
    browser.webNavigation.onCommitted.addListener(onTabLoad); 
} 
function disable() {
    browser.browserAction.setIcon({ path: '/ui/is-off.png', });
    browser.browserAction.setPopup({ popup: '/ui/turn-on.js', });
    browser.webNavigation.onCommitted.removeListener(onTabLoad); 
}
function onTabLoad(details) {
    browser.tabs.executeScript(details.tabId, {
        file: '/gc.js',
        allFrames true,
    }); 
}
enable(); // enable or disable by default

显然，我做错了什么。我是一名善于编码的新手。这是我试图完成的个人项目。

1 个答案:

答案 0 :(得分：3)

您的代码

当您添加switch语句以启用button时，您从未定义button，也未更改其状态。您也没有默认情况，以防button变量不是您在case语句中测试的值之一。

您不应该使用browserAction.setPopup()来设置弹出窗口。设置弹出窗口将导致弹出窗口而不是您的后台页面收到click事件。此外，弹出窗口必须是HTML页面，而不是JavaScript。

请参阅以下部分，了解您需要在onTabLoad()中解决的Firefox错误。

聆听webNavigation.onCommitted不足以涵盖需要注入脚本的所有情况。换句话说，每次加载页面时都不会触发webNavigation.onCommitted。要完全覆盖需要注入脚本的每种情况，您需要在另一个问题中提出这个问题。

var nextButtonState;
browser.browserAction.onClicked.addListener(function (tab) {
    switch (nextButtonState) {
        case 'turn-on':
            enable();
            break;
        case 'turn-off':
        default:
            disable();
            break;
    }
});
function enable() {
    browser.browserAction.setIcon({ path: '/ui/is-on.png', });
    //browser.browserAction.setPopup({ popup: '/ui/turn-off.js', });
    browser.webNavigation.onCommitted.addListener(onTabLoad); 
    nextButtonState = 'turn-off';
} 
function disable() {
    browser.browserAction.setIcon({ path: '/ui/is-off.png', });
    //browser.browserAction.setPopup({ popup: '/ui/turn-on.js', });
    browser.webNavigation.onCommitted.removeListener(onTabLoad); 
    nextButtonState = 'turn-on';
}
function onTabLoad(details) {
    //Add a setTimout to avoid a Firefox bug that Firefox is not quite ready to 
    //  have tabs.executeScript() inject a script when the onCommitted event fires.
    setTimeout(function(){
        chrome.tabs.executeScript(details.tabId, {
            file: '/gc.js',
            allFrames true,
        }); 
    },0);
}
enable(); // enable or disable by default

Firefox webNavigation.onCommitted错误的解决方法

您的onTabLoad()代码需要更改才能使用webNavigation.onCommitted侦听器在Firefox中使用tabs.executeScript()注入脚本（Chrome中不需要这样做）。这是由于Firefox中的一个错误导致tabs.executeScript()在webNavigation.onCommitted监听器中立即执行时失败。我使用的解决方法是在setTimeout(function,0)延迟后注入脚本。这允许Firefox执行设置executeScript()运行所需的环境所需的代码。

function onTabLoad(details) {
    //Add a setTimout to avoid a Firefox bug that Firefox is not quite ready to 
    //  have tabs.executeScript() inject a script when the onCommitted event fires.
    setTimeout(function(){
        chrome.tabs.executeScript(details.tabId, {
            file: '/gc.js',
            allFrames true,
        }); 
    },0);
}

多状态按钮的通用解决方案（例如切换按钮）

我用来使浏览器操作按钮的行为类似于切换的代码如下。我修改了browserButtonStates对象，它描述了按钮的功能和外观，添加和删除了webNavigation.onCommitted侦听器onTabLoad()。有关onTabLoad()的问题，请参见上文。

以下代码比您需要的更复杂。我写它的目的是能够将它从一个项目移动到另一个项目，只需要更改browserButtonStates对象的内容。然后，只需更改该对象，即可更改在每个状态（例如开/关）中执行的图标，文本，徽章文本，徽章颜色和操作。

background.js 

//The browserButtonStates Object describes the states the button can be in and the
//  'action' function to be called when the button is clicked when in that state.
//  In this case, we have two states 'on' and 'off'.
//  You could expand this to as many states as you desire.
//icon is a string, or details Object for browserAction.setIcon()
//title must be unique for each state. It is used to track the state.
//  It indicates to the user what will happen when the button is clicked.
//  In other words, it reflects what the _next_ state is, from the user's
//  perspective.
//action is the function to call when the button is clicked in this state.
var browserButtonStates = {
    defaultState: 'off',
    on: {
        icon         : '/ui/is-on.png'
        //badgeText  : 'On',
        //badgeColor : 'green',
        title        : 'Turn Off',
        action       : function(tab) {
                           chrome.webNavigation.onCommitted.removeListener(onTabLoad);
                       },
        nextState    : 'off'
    },
    off: {
        icon         : '/ui/is-off.png'
        //badgeText  : 'Off',
        //badgeColor : 'red',
        title        : 'Turn On',
        action       : function(tab) {
                           chrome.webNavigation.onCommitted.addListener(onTabLoad);
                       },
        nextState    : 'on'
    }
}

//This moves the Browser Action button between states and executes the action
//  when the button is clicked. With two states, this toggles between them.
chrome.browserAction.onClicked.addListener(function(tab) {
    chrome.browserAction.getTitle({tabId:tab.id},function(title){
        //After checking for errors, the title is used to determine
        //  if this is going to turn On, or Off.
        if(chrome.runtime.lastError){
            console.log('browserAction:getTitle: Encountered an error: ' 
                + chrome.runtime.lastError);
            return;
        }
        //Check to see if the current button title matches a button state
        let newState = browserButtonStates.defaultState;
        Object.keys(browserButtonStates).some(key=> {
            if(key === 'defaultState') {
                return false;
            }
            let state = browserButtonStates[key];
            if(title === state.title) {
                newState = state.nextState;
                setBrowserActionButton(browserButtonStates[newState]);
                if(typeof state.action === 'function') {
                    //Do the action of the matching state
                    state.action(tab);
                }
                //Stop looking
                return true;
            }
        });
        setBrowserActionButton(browserButtonStates[newState]);
    });
});

function setBrowserActionButton(tabId,details){
    if(typeof tabId === 'object' && tabId !== null){
        //If the tabId parameter is an object, then no tabId was passed.
        details = tabId;
        tabId       = null;
    }
    let icon   = details.icon;
    let title  = details.title;
    let text   = details.badgeText;
    let color  = details.badgeColor;

    //Supplying a tabId is optional. If not provided, changes are to all tabs.
    let tabIdObject = {};
    if(tabId !== null && typeof tabId !== 'undefined'){
        tabIdObject.tabId = tabId;
    }
    if(typeof icon === 'string'){
        //Assume a string is the path to a file
        //  If not a string, then it needs to be a full Object as is to be passed to
        //  setIcon().
        icon = {path:icon};
    }
    if(icon) {
        Object.assign(icon,tabIdObject);
        chrome.browserAction.setIcon(icon);
    }
    if(title) {
        let detailsObject = {title};
        Object.assign(detailsObject,tabIdObject);
        chrome.browserAction.setTitle(detailsObject);
    }
    if(text) {
        let detailsObject = {text};
        Object.assign(detailsObject,tabIdObject);
        chrome.browserAction.setBadgeText(detailsObject);
    }
    if(color) {
        let detailsObject = {color};
        Object.assign(detailsObject,tabIdObject);
        chrome.browserAction.setBadgeBackgroundColor(detailsObject);
    }
}

//Set the starting button state to the default state
setBrowserActionButton(browserButtonStates[browserButtonStates.defaultState]);

的manifest.json ：

{
    "description": "Demo Button toggle",
    "manifest_version": 2,
    "name": "Demo Button toggle",
    "version": "0.1",

    "background": {
        "scripts": [
            "background.js"
        ]
    },

    "browser_action": {
        "default_icon": {
            "32": "myIcon.png"
        },
        "default_title": "Turn On",
        "browser_style": true
    }
}
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