I am trying to make clickable links in text strings that launch an activity when clicked. I have used Linkify() to detect links in my text. This function is capable of adding links to text, but only web URLs. I need to turn my output into a ClickableSpan so that I can implement this technique.
How do I get Linkify()'s identified links to become ClickableSpans which direct to an activity?
Below is the code I have used in Linkify:
// Linkify parameters
final static Pattern pattern = Pattern.compile("\\[[^]]*]"); // defines the fact that links are bound by [square brackets]
final String scheme = "http://"; // TODO: Currently this is just a blank link
Linkify.addLinks(linkText, pattern, scheme);
For what you want to achieve, it's probably simpler to just override the startActivity() method in your Activity and intercept the ACTION_VIEW intents with the URLs in your text. Something like this:
public class MyActivity extends Activity {
#Override
public void startActivity(Intent intent) {
final String action = intent.getAction();
if (action.equals(Intent.ACTION_VIEW)) {
// launch our other activity instead
Intent ourIntent = new Intent(this, MyOtherActivity.class);
ourIntent.setData(intent.getData());
super.startActivity(ourIntent);
// we're done!
return;
}
// else, normal handling by the framework
super.startActivity(intent);
}
// the rest of your activity code
}
For reference, here's the source code for URLSpan which will trigger the startActivity() method above.
How do I get Linkify()'s identified links to become ClickableSpans which direct to an activity?
After your call to addLinks(), call getText() to retrieve the Spanned object from the TextView. This object will have a series of URLSpan objects, one per matched link -- you can get an array of those through a call to getSpans(). You will need to note where each those spans start and end (via getSpanStart() and getSpanEnd()), remove the URLSpan, and replace it with your own spans to do what you want.
Related
I have an android application that has to parse fairly large amounts of HTML and place it inside one or more TextViews. So any one of these given text views might contain one more html link. These links are created dynamically and embedded in the rest of the text. It seems the only way I can allow these links to work is by using the following code.
TextView textView = new TextView(mContext);
textView.setAutoLinkMask(0);
textView.setLinksClickable(true);
Linkify.addLinks(textView, Patterns.WEB_URL, "ref://");
textView.setMovementMethod(LinkMovementMethod.getInstance());
textView.append(getSpannable(htmlString));
This works just fine for any http link, I simply added filter to a WebActivity in my a filter in my manifest and call it a day.
My problem however is that I have links that I want to send with additional data not contained in the link itself. Additionally the the extra data I want to send would change based on the target of the link. I cannot do this because the intents are fired based on the HTML data the user clicks.
Is there any way to modify / intercept/ override an Intent fired by my Activity in order to add additional data to it after it has been fired?
Edit With Answer Based on #Tanis.7x Suggestion
In my original question I failed to specify that I was using a Spanned derived from Html.fromHtml(htmlString);
I was able to figured out a solution based on #Tanis.7x answer and this question's accepted answer Android TextView with Clickable Links: how to capture clicks?
TextView textView = new TextView(mContext);
textView.setAutoLinkMask(0);
textView.setLinksClickable(true);
Linkify.addLinks(textView, Patterns.WEB_URL, "ref://");
textView.setMovementMethod(LinkMovementMethod.getInstance());
textView.append(getHtmlStringForTextView(Html.fromHtml(htmlString)));
private SpannableStringBuilder getHtmlStringForTextView(String html)
{
CharSequence sequence = Html.fromHtml(html);
SpannableStringBuilder strBuilder = new SpannableStringBuilder(sequence);
URLSpan[] urls = strBuilder.getSpans(0, sequence.length(), URLSpan.class);
for(URLSpan span : urls) {
makeLinkClickable(strBuilder, span);
}
return strBuilder;
}
private void makeLinkClickable(SpannableStringBuilder spannableStringBuilder, final URLSpan span)
{
int start = spannableStringBuilder.getSpanStart(span);
int end = spannableStringBuilder.getSpanEnd(span);
int flags = spannableStringBuilder.getSpanFlags(span);
ClickableSpan clickable = new ClickableSpan() {
public void onClick(View view) {
//handle click here
}
};
spannableStringBuilder.setSpan(clickable, start, end, flags);
spannableStringBuilder.removeSpan(span);
}
You cannot intercept intents after they are fired.
If you look at the source of URLSpan (which is responsible for handling links in TextViews), you will see that in it's onClick() method it creates an appropriate Intent, then fires it off with a call to context.startActivity(intent);. At that point in time the Intent is out of your hands and responsibility for handling the Intent lies within the Android framework.
You can, however, get the behavior you desire. First you need to create your own URLSpan subclass. Override onClick() and handle the click however you want.
public class CustomUrlSpan extends URLSpan {
public CustomUrlSpan(String url) {
super(url);
}
/* You may want to properly support the ParcelableSpan interface as well */
#Override
public void onClick(View widget) {
Uri uri = Uri.parse(getURL());
Context context = widget.getContext();
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
intent.putExtra(Browser.EXTRA_APPLICATION_ID, context.getPackageName());
// Put your custom intent handling in here
try {
context.startActivity(intent);
} catch (ActivityNotFoundException e) {
Log.w("URLSpan", "Actvity was not found for intent, " + intent.toString());
}
}
}
Then, instead of using Linkify to make your links clickable, you will need to create the spans yourself. Take a look at the Linkify source if you need a starting point- you'll probably want to do something very similar to addLinks(), but with your CustomUrlSpan instead of the standard URLSpan.
I have a main activity which has 2 fragments. The main activity has a SearchView in the action bar. Both the fragments have a list of large number of strings, List<String>.
The flow is:
User enters Fragment I --> Selects a string (lets say Selection1) --> Based on Selection1 a list of strings is populated in the second fragment --> Here the user selects a second String ---> Processing based on these two strings.
Now since both the fragments contain a large number of strings, the user enters a query in the SearchView, which filters the list and reduces it to a smaller list displayed in the SearchableActivity.
Now the problem is how does the SearchableActivity get access to these two List<String> to filter them based on the query and display a reduced list to the user.
Currently what I have done is overridden onSearchRequested and pass the data as
#Override
public boolean onSearchRequested()
{
Bundle appData = new Bundle();
appData.putString(FRAGMENT_ID, "Fragment_A");
appData.putStringArrayList(SEARCH_LIST, searchList);
startSearch(null, false, appData, false);
return true;
}
Is there a better way or standard way by which this problem can be handled i.e. an implementation that allows data to be based from my MainActivity to SearchableActivity?
Edit: Adding code. Showing how data is set in the Fragment. onDataReceived is called from the HttpManager which receives the data.
#Override
public void onDataReceived(String type,final Object object)
{
switch(type)
{
case PopItConstants.UPDATE_LIST:
getActivity().runOnUiThread(new Runnable() {
#Override
public void run()
{
updateCinemaList((List<String>) object);
}
});
break;
}
}
public void updateDataList(List<String> data)
{
this.dataList = data;
spinner.setVisibility(View.GONE);
mAdapter.updateList(dataList);
}
I just answered a similar question a few minutes ago, at how can I send a List into another activity in Android Studio
I encourage you to rethink your pattern of simply passing data around among Activities and Fragments. Consider creating one or more data models (non-Android classes) for your application, and making these models available to the Android classes (Activities, Fragments, etc.) that need them.
Remove all of the data storage and manipulation code from your Activities and Fragments, and put it into the model(s).
Okay... So this is how I did it.
Basically, the data received in the two fragments was not simply List<String> but they were models viz. Cinema and Region which contained details other than names including location, rating etc.
So, firstly, I made an interface ISearchable
public Interface ISearchable
{
// This contains the Search Text. An ISearchable item is included
// in search results if query is contained in the String returned by this method
public String getSearchText();
//This is meant to return the String that must be displayed if this item is in search results
public String getDisplayText();
//This is meant to handle onClick of this searchableItem
public void handleOnClick();
}
Both the Cinema and Region models implemented ISearchable.
After this, I used a singleton class DataManager in which I maintained a List<ISearchable> currentSearchList.
public class DataManager
{
.....<singleton implementation>....
List<ISearchable> currentSearchList;
public void setSearchList(List<ISearchable> searchList)
{
this.currentSearchList = searchList;
}
public List<ISearchable> getSearchList()
{
return this.currentSearchList;
}
}
So whenever a fragment (either Fragment_A or Fragment_B) is loaded, it updates this currentSearchList, so that when the SearchableActivity performs search all it has to do is DataManager.getInstance().getSearchList() and then use this list for filtering out a list of matching items.
This is how I handled the problem of having Lists in Activity other than the SearchableActivity using which search needs to be performed.
I understand this might not be the best solution, so, I look forward to suggestions and criticisms, and using that to be arrive at a better solution.
So I'm still working on my first little app here, new to Android and Java, so I'm stuck on a basic little problem here. Answers to my first questions were really helpful, so after researching and not coming up with anything, I thought I'd ask for some more help!
The idea is that on another screen the user makes a choice A, B, C, or D, and that choices is passed as a string through the intent. OnResume checks if the choice is not null and sets an integer that corresponds to that string. Later when the user pushes another button, some if else logic checks that int and performs and action based on which was chosen. The problem is that the App crashed at onResume.
I learned that I have to use equals(string) to compare string reference, but maybe the problem is that I am trying to compare a string in reference to a literal string? Any help would be greatly appreciated.
Thanks!
protected void onResume() {
super.onResume();
// Get the message from the intent
Intent intent = getIntent();
String choice = intent
.getStringExtra(ExtensionSetupSlector.TORQUE_SETUP);
// Create the text view
TextView displayChoice = (TextView) findViewById(R.id.displayChoice);
if (!choice.equals("")){
displayChoice.setText(choice);
if (choice.equals("A")) {
myChoice = 1;
}
if (choice.equals("B")) {
myChoice = 2;
}
if (choice.equals("C")) {
myChoice = 3;
}
if (choice.equals("D")) {
myChoice = 4;
}
}
}
myChoice is declare right after ...extends Activity{ Also I'm not quite sure If this should really be in onResume, but it was working before I started try to set myChoice in the onResume (when I was just displaying the choice). Thanks again!
Change if (!choice.equals("")) to check for null instead. Otherwise your app attempts to access an empty reference and crashes.
in my android application at some event in an activity I want to ask the user for a name (string). I know how to do this: call showDialog, create the dialog in the Activity.onCreateDialog method (I need to supply a string for the label) and handle the result in the onClick of the dialog. This works fine and to my satisfaction.
BUT this way I have three different places, where this simple task spreads throughout the code of my activity. I would much more prefer to keep this code together, to write some code like this:
string result;
if (showSimpleEditDialog(idForLabelString, result)==DIALOG_OK)
{
// do something with the result
}
or maybe with a class instance
SimpleEditDialog dlg = new SimpleEditDialog(idForLabelString);
if (dlg.showModal()==DIALOG_OK)
{
string result = dgl.getResult();
// do something with the result
}
(The "idForLabelString" would be some resource id for the label to use, DIALOG_OK would be some constant returned when the user clicks OK)
I know, I would have to write this methodes or this class. But for better readibility of my code I would do it. Any suggestions?
Thank you,
Gerhard
"BUT this way I have three different places, where this simple task spreads throughout the code"
So why don't you create a Method for this task? What you are talking about sounds like some sort of 'ActionListener' to me. This can be done in Java/Swing, but not in Android.
But, if you have three Dialogs, which all need to do the same when "YES" e.g. "NO" is pressed, you could define the 'DialogInterface.OnClickListener()' as a global inner-Class (or in a second class which extends the 'onClickListener') and then use it for all the Dialogs.
Now actually the problem with modal dialogs is mostly a problem with programm flow. You want to keep things together that belong together. You want to display a dialog that returns "ok" or "cancel" and additionaly e.g. a string that the user entered into one of the dialog widgets.
I do not want to write half of the code up to the line where I need the result of the dialog on one place and the rest of the code on another place namely the onClickListener of the dialog.
In some scenarios the first dialog might invoke a second dialog e.g. to specify a color which is not in the list of the first dialog's ListView.
Your code will be scattered all over the place (in each dialog's button onClickListener) and will be hard to read or to maintain.
Now after having written some unclear code like that I came up with the following solution which certainly respects the android design guides.
Instead of directly showing a dialog I create a Handler derived class which handles messages.
I send it a first message which creates and shows a dialog. It also forwards the handler to the dialog and the diaolg in it's onStop method sends another message to the handler, indicating the end of the dialog. There you can examine the dialogs properties, the contents of the edit fields or whether it was stopped with OK or CANCEL.
Now in the message handler all the logic of the task sits in different cases of the messages arg1 value.
Some cases might be skipped (e.g. the user selected a standard color and did not need a special color dialog).
The dialogs are independant of the scenario from which they are called and in their code only reflect their simple task (selecting from a list, some checkboxes etc.). They may be reused from other scenarios.
Following a kind of a template how to use this approach:
public class DoSomethingWithDialogs extends Handler
{
Context context; // from which it was called
final static int stepBegin = 0;
final static int stepNext = 1;
final static int stepSomethingElse = 2;
final static int stepLast = 3;
protected DoSomethingWithDialogs(Context context)
{
this.context = context;
}
public static void start(Context context)
{ // this is the main (only) entry point from outside
DoSomethingWithDialogs st = new DoSomethingWithDialogs(context);
st.sendMessage(st.obtainMessage(0, stepBegin, 0));
}
#Override
public void handleMessage(Message msg)
{
// step by step handling the task
switch (msg.arg1)
{
case stepBegin:
{
SomeDlg somedlg = new SomeDlg(context, this, stepNext);
// when the dialog closes, it sends a message to this with stepNext as arg1
somedlg.show();
}
break;
case stepNext:
{ // this message was send by the dialog when it finished
SomeDlg somedlg = (SomeDlg) msg.obj;
if (msg.arg2 == Dialog.BUTTON_NEGATIVE)
{
// has been canceled, nothing to do
} else
{
if (somedlg.someProperty)
{
} else
{
sendMessage(obtainMessage(0, stepSomethingElse, 0));
}
}
}
break;
case stepSomethingElse:
break;
}
}
}
I have an android context menu with various selections and depending on the user selection I want to start an intent. The intent starts the same activity for all the buttons but will contain different String variables depending on the selection. I am currently using a switch, case methodology for my click listener but keep running into 'duplicate local variable' problems as I try to eliminate code repetition! If anyone could provide a-bit of pseudo-code that would be even better!
It's hard to tell without seeing some code, but "duplicate local variables" together with "switch case" makes me think you're declaring a variable in one of the cases with the same name as a variable from another case.
Code within different cases of the same switch is all in the same scope, unless you surround the code within a case with brackets, like this:
switch(VALUE) {
case A: {
String string = "";
}
case B: {
//Same variable name, possible since it's in a different scope now.
String string = "";
}
}
So either use brackets, or simply make sure you're using different variable names across the cases.
you can use intent.putExtra(String name, String value) and push it to the other activity.
Pseudo code:
Button1.value = "X" ;
Button2.value = "Y" ;
onClickListner(View v) {
Intent intent = new Intent() ;
intent.putExtra("ButtonValue",
v.value() ) ;
// extra code goes here...
}
Hope this is what you were looking for..
VInay
I like to use set/getTag(Object), as you can put any type you like into it (as long as you're careful about getting it out again):
button1.setTag(MyClass.STATIC_INT_1);
button2.setTag(MyClass.STATIC_INT_2);
button1.setOnClickListener(Click);
button2.setOnClickListener(Click);
private OnClickListener Click(View v) {
Intent intent = new Intent() ;
intent.putExtra("Value", Integer.parseInt(v.getTag().toString()) ) ;
ยทยทยท
}