I am a total newbie at android (as well as this is my first post on StackOverflow) and I was wondering if there is a way of passing control from a web view displaying HTML to the actual android code. To make it a little more clear:
Suppose I have a HTML code that I am displaying in the web view in android, now I click the submit button (which is in the HTML page), is there a way to use that click to call a method in the android code?
A very high level view can be something like
if(Submit is clicked){ //submit would be the submit button in the html page
call xyz(); //xyz would be the android method
}
I would really appreciate it if you guys can help.
It is possible, refer to this.
There is a simple example there that should kick you off.
Javascript is the word of the day.
Use addJavaScriptInterface() to put a reference in the Javascript environment to some Java object.
Here is a sample application demonstrating this, to allow a page in a WebView to retrieve a location from the activity hosting the WebView.
You can use WebView addJavascriptInterface to export your method to the HTML page, here is a relevant snippet:
WebViewVariable.addJavascriptInterface(new MyJavaScriptInterface(context), "Android");
Here is the code for MyJavaScriptInterface :
class MyJavaScriptInterface {
Context localContext;
public MyJavaScriptInterface(Context ctx) {
localContext = ctx;
}
public void pageReady() {
// do your work here
}
}
You can now call the above class's method pageReady() from your HTML page like this Android.pageReady(). Remember though that you can only pass primitive data types (If I remember correctly).
Hope it helps
Related
How do I get getString in fragment, I have tried to solve it with snippets of code on this but it did not work to tap
chronology
-ok so in the uploaded image there are some 6 items in the recyclerview that line up the grid, I try to make it to the String of the name as I have included the code but the code I press [commant + tap] displays the message {public statuc int} , but it can't be tapped to go to the next page, but if I try to use the usual string as I have included the code, it works on the next page
get an error public static int
dataProduct.add(Products(R.drawable.ic_electricity, getString(R.string.electricity), true))
I've looked for a solution in this forum but it still hasn't worked, but if I use the code below it works
dataProduct.add(Products(R.drawable.ic_electricity, "Electricity", true))
maybe I'll send a picture, below, in this case I will take the string but can't be tapped like the image below
image getString
getString() is a method that comes from a context. In a fragment, this context is commonly provided by the activity hosting the fragment. To use the activity to get a resource, just call getActivity() (which in Kotlin can be written just as activity):
activity.getString(…)
I have multiple activities where I show different instances of WebViews. Lets say I visit www.stackoverflow.com in one activity. If I see a link that points to this adress, it will be shown in purple (showing that it has been visited). Now, I have tried clearing every WebView object in multiple ways, and in different stages (including after loading URL's for every WebView object). E.g., these are the functions I've tried calling for each WebView object:
Just after finding each layout element in my activities' onCreate (findViewById...), I am setting:
wv.getSettings().setAppCacheEnabled(false);
wv.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
And then, in onPageFinished in my WebViewClient:
wv.clearHistory();
wv.clearCache(true);
wv.clearFormData();
wv.clearMatches();
wv.clearSslPreferences();
I am only looking for some guidance on how to think on this matter, rather than a full code example. Hence, I do not provide full code for my specific case.
Edit:
Actually, if there is a way to clear a SPECIFIC website URL from an instance of a WebView, I would really prefer this.
I have tried overridding doUpdateVisitedHistory like this:
#Override
public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
super.doUpdateVisitedHistory(view, url, isReload);
view.clearHistory();
}
I am creating an Android Browser and within my browser i am making a Favorites page.
In my favorite page, i have an EditText, where i insert the adress of the website i want to add, a remove button which removes all favorites and a TextView where the added websites are displayed.
My question is ...how can i make the adresses displayed in the TextView to be links, not only strings, BUT to be opened inside my browser?
All my tries so far ended up opening it with the phone's browser. My browser is structured like this: A menu, which is an OnListItemClick, where i can select HomePage, which has the main thing where you can browse the internet, with back and forward, refresh buttons.
In the menu, after the HomePage, i have Favorites, History and Settings. I need it to start the HomePage and to acces the site when i click the link from the favorites TextView. Can anyone give me an idea how to do it? I am sure i need to make a huge method for that, but I don't know how to start.
Know this is pretty late. Just think others might also find this useful.
You can implement your own ClickableSpan to achieve that. You can create a Spannable from scratch and assign to TextView like:
Spannable text = Spannable.newSpannable("Source text with link");
ClickableSpan link = new ClickableSpan {
public abstract void onClick (View widget) {
// Implement your own link behaviour
}
}
text.setSpan(clickable, startPos, endPos, flags);
textView.setText(text);
Or, if your source is html, you can use Html.fromHtml("Source text with <a href='whatever'>link</a>") which parses the HTML and converts links into URLSpan for you. You then need to replace all URLSpan with your own ClickableSpan like above. (see Spanned#getSpans and Spannable)
This can be tedious. Thus I created a library Textoo to simplify the matter. With Textoo you can achieve the same like:
Spanned linksLoggingText = Textoo
.config("Links: <a href='http://www.google.com'>Google</a>")
.parseHtml()
.addLinksHandler(new LinksHandler() {
#Override
public boolean onClick(View view, String url) {
Log.i("MyActivity", "Linking to google...");
return false; // event not handled. Continue default processing i.e. link to google
}
})
.apply();
I have an application in which an activity communicates with our server and gets the outstanding amount details. I want users to pay the outstanding amount using a payment gateway. for Payment Gateway, I have to call web page from webview and transfer outstanding amount details and other credentials from activity to the page loaded in webview. At the end of transaction I once again need to get some parameters back from webpage in webview to activity.
This is a two way communication which I want to achieve between an activity and a page loaded in webview. I tried to find out a way to do it but could not find a simple example which does such exchange.
You could achieve what you want using a javascript WebAppInterface as demonstrated here.
The main concept is that, you create a javascript interface inside the Activity holding your WebView.
private class WebPayInterface {
int amount;
boolean success;
#JavascriptInterface
public void PaymentFinished(int amount, boolean success) {
this.amount = amount;
this.success = success;
// do whatever you want in the parent activity.
}
}
Add the interface to your webView
webView.addJavascriptInterface(new WebPayInterface(), "WebPayInterface");
Finally in your html code using javascript you can call
WebPayInterface.PaymentFinished(100, true);
You can make use of Intent.putExtra() while navigating using Intents, Shared Preferences and also Bundle. Please read Android documentation for Shared Preferences, Intents, Bundle
Everything I've read about Intents talks about using them to push data, or to start one Activity from another Activity. I want to pull data from an Activity that's already running.
The Tab Layout tutorial at http://developer.android.com/resources/tutorials/views/hello-tabwidget.html illustrates what I want to do. (My app is doing some engineering calculations instead, but the tutorial code provides a good analogy to my app.) The tutorial creates an app with three tabs, and each tab hosts a separate activity.
To expand on the example in the tutorial, suppose I select an artist in the Artists tab/activity. I want to be able to select the Albums tab/activity and have it display all the albums featuring that artist.
It seems to me that I need to use an Intent to do this. All of the tutorials I've found assume that I would create a "See albums" Button in the Artists tab/activity, and that pressing the Button would execute an Intent that starts the Albums activity and passes artistName.
I DO NOT want to create that Button. Real estate on the Artists layout is precious, and I have a perfectly good Albums tab, AND the HelloTabWidget activity already contains an intent to create the Albums tab.
Besides, a user will want to skip back and forth between Album and Artist in order to change artist selections, and the tabs are a perfectly good way to do this. There's no need to complicate the UI with another button.
So how can I have the Albums activity PULL artistName from the Artists activity when the Albums tab is selected (or the Albums layout is displayed), rather than have the Artists activity START Albums and PUSH the artistName?
Equivalents I can think of from other programming worlds:
Global variables. Discouraged in Android devt, right? And if they do exist, what are they called?
A getter, like artistName = Artists.getArtistName(); . I get the feeling that it's not that easy.
Writing to, and reading from, a file - that is, mass storage or non-volatile memory. I don't need the artistName value to be permanent. It will be reset to null every time the user launches the application.
So how is it done in the Android world? Do I use an Intent - and if so, how?
Global variables were the right answer.
I thought Java discouraged their use, but a couple of links that appeared in the "Related" links on the right margin of this window mentioned them directly. One was "Android: How to declare global variables?" and the other was "how to pass value betweeen two tab in android". Both pointed to the Application Class as the place to define global variables and methods. Armed with this new knowledge, I found an article called "Android Application Class" on the Xoriant blog that expanded on the StackOverflow answers.
It's best to review those three links first. I need to add some tips to what those authors have said.
Your Application class has to be in its own separate file. (That might be a "duh" to some people, but not to everybody.) Here's a good framework for an example called Something.java:
public class Something extends Application {
// Put application wide (global) variables here
// Constants are final, so they don't have to be private
// But other variables should be declared private;
// use getters/setters to access them
public final boolean FEET = false;
public final boolean METERS = true;
private boolean units = FEET;
#Override
public void onCreate() {
super.onCreate();
// Put any application wide (global) initialization here
}
// Put application wide (global) methods here
public boolean getUnits() {
return units;
}
public void setUnits(boolean whichOne) {
units = whichOne;
}
}
I'm using Eclipse with the ADT plug-in, in Windows XP. Eclipse doesn't always behave properly if you edit XML code directly, so it's best to open AndroidManifest.xml, then select the Application tab and enter your application name in the Name field. You don't need to put a dot or period in front of the name. Just type in the name of your class, like "Globals" or "MyApplication" or whatever. (Note that this is the default application in your Manifest. You don't have to create a separate <application></application> tag.
This step may not be necessary on an actual Android device, but it was necessary for the emulator: you need to use the getApplicationContext() command in every onCreate() and every method that will be accessing the global variables and methods. I tried to put it outside of onCreate() with the rest of my activity wide variables, and it didn't work. Putting it inside every method seems wasteful, but both the emulator and the Android device work fine with it that way. Here's a sample showing how I used it:
public void fooBar() {
// Access to global variables and methods
final Something s = (Something)getApplicationContext();
// ...
// This next line demonstrates both a global method and a global variable
if (s.getUnits() == s.FEET) {
// do something with feet
} else {
// do something with meters instead
}
// ...
}
Those were the only hiccups I encountered. The three references that I have listed, taken together, are otherwise pretty complete.