Introduction
In this article I describe how to create a Windows Store App for panning and scrolling large images using JavaScript. Panning and scrolling is used to allow an end-user to reach additional content that otherwise would not fit into a view. There are a few types of panning and scrolling to consider:
- Horizontal: User can move content left/right.
- Vertical: User can move content up/down both axes.
- Unrailed: User is free to move the content in any direction.
- Railed: User motion is locked to an axis, if close enough to the axis.
With the new ms-overflow-style property, you can control the type of scrollbar and when it appears.
I assume you can create a simple Windows Store App using JavaScript. For more help visit Simple Windows Store Apps using JavaScript.
To start the creation of the app, add two JavaScript pages by right-clicking on the js folder in the Solution Explorer and select Add > new item > JavaScript Page and then give an appropriate name. In the same way, add one HTML page to your project.
![panning-in-windows-store-apps.jpg]()
Write the following code in default.html:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<link rel="stylesheet" href="//Microsoft.WinJS.1.0/css/ui-light.css" />
<script src="//Microsoft.WinJS.1.0/js/base.js"></script>
<script src="//Microsoft.WinJS.1.0/js/ui.js"></script>
<link rel="stylesheet" href="/css/default.css" />
<script src="/js/script1.js"></script>
<script src="/js/default.js"></script>
</head>
<body role="application">
<div id="rootGrid">
<div id="content">
<h1 id="featureLabel"></h1>
<div id="contentHost"></div>
</div>
</div>
</body>
</html>
Write the following code in default.js:
(function () {
"use strict";
var AppTitle = "";
var pages = [
{ url: "page.html" }
];
function activated(eventObject) {
if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) {
eventObject.setPromise(WinJS.UI.processAll().then(function () {
var url = WinJS.Application.sessionState.lastUrl || pages[0].url;
return WinJS.Navigation.navigate(url);
}));
}
}
WinJS.Navigation.addEventListener("navigated", function (eventObject) {
var url = eventObject.detail.location;
var host = document.getElementById("contentHost");
host.winControl && host.winControl.unload && host.winControl.unload();
WinJS.Utilities.empty(host);
eventObject.detail.setPromise(WinJS.UI.Pages.render(url, host, eventObject.detail.state).then(function () {
WinJS.Application.sessionState.lastUrl = url;
}));
});
WinJS.Namespace.define("app", {
AppTitle: AppTitle,
pages: pages
});
WinJS.Application.addEventListener("activated", activated, false);
WinJS.Application.start();
})();
Write the following code in page.html:
<!DOCTYPE html>
<html>
<head>
<title></title>
<link rel="stylesheet" href="/css/panning.css" />
<link rel="stylesheet" href="/css/default.css" />
<script src="/js/script.js"></script>
</head>
<body>
<div data-win-control="app.pageInput">
<div id="selectGrid">
<label id="PanningTypeLabel">Select:</label>
<select size="1" id="PanningType" aria-labelledby="PanningTypeLabel">
<option selected="selected" value="None">None</option>
<option value="Horizontal">Horizontal</option>
<option value="Vertical">Vertical</option>
<option value="Unrailed">Unrailed</option>
<option value="Railed">Railed</option>
</select>
<br />
<label id="ScrollbarStyleLabel">Set style:</label>
<select size="1" id="ScrollbarStyle" aria-labelledby="ScrollbarStyleLabel">
<option selected="selected" value="none">none</option>
<option selected="selected" value="scrollbar">scrollbar</option>
<option selected="selected" value="-ms-autohiding-scrollbar">-ms-autohiding-scrollbar</option>
</select>
</div>
</div>
<div data-win-control="app.pageOutput">
<div id="page1_Scroller" class="ManipulationContainer None">
<img alt="abc" src="/images/abc.jpg" class="row1 col1" />
</div>
</div>
</body>
</html>
Write the following code in script.js:
(function () {
"use strict";
var page = WinJS.UI.Pages.define("page.html", {
processed: function (element, options) {
document.getElementById("PanningType").addEventListener("change", changePanningType, false);
document.getElementById("ScrollbarStyle").addEventListener("change", changeOverflowStyle, false);
}
});
function changePanningType(changedEvent) {
var myScrollElement = document.getElementById("page1_Scroller");
var panType = changedEvent.target.options.value;
myScrollElement.className = "ManipulationContainer " + panType;
}
function changeOverflowStyle(changedEvent) {
var myScrollElement = document.getElementById("page1_Scroller");
myScrollElement.style["-ms-overflow-style"] = changedEvent.target.options.value;
}
})();
Write the following code in script1.js:
(function () {
var pageOutput = WinJS.Class.define(
function (element, options) {
element.winControl = this;
this.element = element;
new WinJS.Utilities.QueryCollection(element)
.setAttribute("role", "region")
.setAttribute("aria-labelledby", "outputLabel")
.setAttribute("aria-live", "assertive");
element.id = "output";
this._addOutputLabel(element);
this._addStatusOutput(element);
}, {
_addOutputLabel: function (element) {
var label = document.createElement("h2");
label.id = "outputLabel";
label.textContent = "Output";
element.parentNode.insertBefore(label, element);
},
_addStatusOutput: function (element) {
var statusDiv = document.createElement("div");
statusDiv.id = "statusMessage";
element.insertBefore(statusDiv, element.childNodes[0]);
}
}
);
var currentpageUrl = null;
WinJS.Navigation.addEventListener("navigating", function (evt) {
currentpageUrl = evt.detail.location;
});
WinJS.log = function (message, tag, type) {
var statusDiv = document.getElementById("statusMessage");
};
function activated(e) {
WinJS.Utilities.query("#featureLabel")[0].textContent = app.AppTitle;
}
WinJS.Application.addEventListener("activated", activated, false);
WinJS.Namespace.define("app", {
pageOutput: pageOutput
});
})();
Output:
![scrooling-in-windows-store-apps1.jpg]()
Summary
In this app I described panning and scrolling an image in a Windows Store app using JavaScript. I hope this article has helped you to understand this topic. Please share if you know more about this. Your feedback and constructive contributions are welcome.