I have a button which is called Check, I want it to be invisible and visible as I click each time on it, as If its visible and I clicked it will become invisible and verse vies !
But my code doesn't work ! any ideas ?
Button Check ;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings);
Check = (Button)findViewById(R.id.checkButton);
Check.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View View) {
if (View.getVisibility() == android.view.View.VISIBLE)
View.setVisibility(android.view.View.INVISIBLE);
else if (View.getVisibility() == android.view.View.INVISIBLE)
View.setVisibility(android.view.View.VISIBLE);
}
});
In my activity its visible at the beginning and when I click on it, it become invisible, BUT when I click again it stays invisible !
Change your code to this,
Check.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (v.isShown())
v.setVisibility(View.INVISIBLE);
else
v.setVisibility(View.VISIBLE);
}
But i think problem is, when button goes invisible, you are not getting any click event on it. First make sure that onClick method get call when button is invisible.
An invisible button will not dispatch any interaction event. So instead of setting button's visibility to the invisible, you can set a transparent or blank background or something like that.
But i personally believe, you should change your use-case because why one will click on the invisible button.
Try This:
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="abcd" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:onClick="abc"
android:text="Button" />
</LinearLayout>
public void abc(View v) {
v.setVisibility(View.INVISIBLE);
}
public void abcd(View v) {
v.findViewById(R.id.button1).setVisibility(View.VISIBLE);
}
Invisible Items don't receive on-click event. So the only way you can receive a click on invisible is by receiving on some other view in place of the invisible view. The above solution wraps the button in a layout, so when button is invisible the on-click is passed on to layout, which handles the event and do accordingly. If you have a high usage of such layout you can also create a custom button with above mechanism.
Related
The premise is quite simple. I have a list of items, and each item has a TextView containing the title of the item, and a Switch showing whether the item is on or off. Instead of tapping on the Switch to toggle the item being on or off, I want to be able to click anywhere on the item to toggle it. Basically:
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:onClick="toggleSwitch">
<TextView
android:id="#+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<Switch
android:id="#+id/switch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</android.support.constraint.ConstraintLayout>
However, this will create a nested layout when used in a screen, which might be bad for performance. I was wondering, since this ConstraintLayout is literally just a container with an onClick, whether there was a way to implement this layout in a way which avoids nested layouts. Thanks!
You can just give your textView and your button the same method that will be called on click, that way on every view click (anywhere on the item) you will call your method.
For example:
textView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//change you switch state
}
});
switch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//change you switch state
}
});
I am trying to build a dynamic UI, but when I add the onClick method to the button whenever I push the button I go back to my previous activity. Any ideas on how to fix it?
my button's code: (the addMenu method is never run in the activities class)
<Button
android:text="New Menu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/newButton"
android:layout_weight="1"
android:onClick="addMenu"/>
here is my addmenu code although no matter what goes in here(even if nothing at all) it still won't work
public void addMenu()
{
LinearLayout layout = (LinearLayout) findViewById(R.id.backLayer);
Button newButton = new Button(this);
newButton.setText("menu "+menu);
layout.addView(newButton);
menu++;
}
whenever I push the button I go back to my previous activity.
Sounds like your app is crashing and restarting... read the logcat, and you'd see something along the lines that your method signature is wrong.
android:onClick="addMenu" needs a method of public void addMenu(View v).
Or just use Java to set the button listener and remove android:onClick.
findViewById(R.id.newButton).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
addMenu();
}
}
try this
/**
* #param v android:id="#+id/newButton"
*/
public void addMenu(View v)
{
LinearLayout layout = (LinearLayout) findViewById(R.id.backLayer);
Button newButton = new Button(this);
newButton.setText("menu "+menu);
layout.addView(newButton);
menu++;
}
I have a simple LinearLayout that consists of a TextView and an EditText. The behaviour that I'd like to achieve is to be able to click on the EditText and handle it like normal, but treat the encompassing LinearLayout as a button that launches a new activity.
So for example, if the user clicks the space around the button in the view, a new activity is launched. If the user clicks on the EditText, then the keyboard appears and the user can populate the EditText.
Here is the simple onClickListener for the layout, which simply states that it has been clicked:
LinearLayout test = (LinearLayout)findViewById(R.id.linearLayout1);
test.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0) {
System.out.println("layout clicked");
}
});
And the EditText has an OnFocusChangeListener that will simply state when it has gotten focus:
#Override
public void onFocusChange(View v, boolean hasFocus) {
System.out.println("EditText clicked");
}
Results:
-When the user clicks on the layout, the result "layout clicked" is correct
-When the user clicks on the edittext, the result is "layout clicked" followed by "EditText clicked", which is not correct. I'd like to ignore the linear layout's onClick event for this case.
Try creating a FrameLayout that contains a LinearLayout containing the TextView and place the EditText above the LinearLayout. This way you will not need to change anything about the listeners.
So it would be like this:
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</LinearLayout>
<EditText
android:id="#+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="200dp" />
</FrameLayout>
Note: use margins to adjust the position of the EditText
I guess something like this should work, although it isn't the cleanest solution.
Declare a runnable that should be executed when the layout is clicked.
final Handler handler = new Handler();
Runnable layoutPressed = new Runnable() {
public void run() {
// LAYOUT CLICKED
}
};
Then start this runnable in your layout onClickListener.
LinearLayout test = (LinearLayout)findViewById(R.id.linearLayout1);
test.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0) {
handler.postDelayed(layoutPressed, 100);
}
});
Cancel the runnable in onFocusChange.
#Override
public void onFocusChange(View v, boolean hasFocus) {
handler.removeCallbacks(layoutPressed);
// EditText clicked
}
So whenever you click the editText, the onClick of your layout will get called first, but the actions will get cancelled when onFocusChange of the editText is called.
When you click the layout, onClick will get called and will execute its actions with a 100 msec delay.
You might have to modify the delay of the runnable.
I have a TextView with the android:onClick attribute. When clicked, the TextView disappears. I don't want the TextView to disappear when clicked. Any ideas?
Edit:
<TextView android:id="#+id/textView1"android:text="Click Me!"
android:layout_width="wrap_content"
android:layout_height="wrap_content" android:onClick="processClick"
android:clickable="true"/>
http://i1179.photobucket.com/albums/x386/jenningsr2006/unclicked.png
http://i1179.photobucket.com/albums/x386/jenningsr2006/clicked.png
Edit
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.example);
TextView t = (TextView)findViewById(R.id.textView1111);
t.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
// Do some job here
Toast.makeText(getApplicationContext(), "Clicked", Toast.LENGTH_SHORT).show();
}
});
Clicking it does the operation correctly, that's not the problem. When I "mousedown" on the TextView, it disappears, then reappears on "mouseup".
I thought I had the same problem but it turned out the textview was not dissapearing, rather the color was changing so that it was the same as the background color. Thus it appeared hidden but it really was there. You can set the clicked color of the text view by setting it's color state list resource
http://developer.android.com/guide/topics/resources/color-list-resource.html
Have you registered a method processClick? There is no need to do it this way. Remove the clickable property and also onClick property. More simple approach is to set onClick listener from the code, for example in onCreate method:
TextView text = (TextView) findViewById(textView1);
text.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
// Do some job here
}
});
The view becomes clickable automatically when you set an on click listener. Good luck
I have created a layout that contains two buttons, Next and Previous. In between the buttons I'm generating some dynamic views. So when I first launch the application I want to disable the "Previous" button since there wont be any previous views. I also want to disable the "Next" button when there are not more views to display. Is there anyway to disable the buttons?
Did you try this?
myButton.setEnabled(false);
Update: Thanks to Gwen. Almost forgot that android:clickable can be set in your XML layout to determine whether a button can be clickable or not.
Yes it can be disabled in XML
just using:
<Button
android:enabled="false"
/>
You can't enable it or disable it in your XML (since your layout is set at runtime), but you can set if it's clickable at the launch of the activity with android:clickable.
You just write a single line of code in your activity
Button btn = (Button) findViewById(R.id.button1);
btn.setEnabled(false);
When you want to enable the same button just write
Button btn = (Button) findViewById(R.id.button1);
btn.setEnabled(true);
In Java, once you have the reference of the button:
Button button = (Button) findviewById(R.id.button);
To enable/disable the button, you can use either:
button.setEnabled(false);
button.setEnabled(true);
Or:
button.setClickable(false);
button.setClickable(true);
Since you want to disable the button from the beginning, you can use button.setEnabled(false); in the onCreate method.
Otherwise, from XML, you can directly use:
android:clickable = "false"
So:
<Button
android:id="#+id/button"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="#string/button_text"
android:clickable = "false" />
In my case,
myButton.setEnabled(false);
myButton.setEnabled(true);
is working fine and it is enabling and disabling the button as it should. But once the button state becomes disabled, it never goes back to the enabled state again, although it's clickable. I tried invalidating and refreshing the drawable state, but no luck.
myButton.invalidate();
myButton.refreshDrawableState();
If you or anyone having a similar issue, what works for me is setting the background drawable again. Works on any API Level.
myButton.setEnabled(true);
myButton.setBackgroundDrawable(activity.getResources().getDrawable(R.drawable.myButtonDrawable));
In Kotlin, if you refer the Button View with id then, enable/disable button as like
layout.xml
<Button
android:id="#+id/btn_start"
android:layout_width="100dp"
android:layout_height="50dp"
android:text="#string/start"
android:layout_alignParentBottom="true"/>
activity.kt
btn_start.isEnabled = true //to enable button
btn_start.isEnabled = false //to disable button
With Kotlin you can do,
// to disable clicks
myButton.isClickable = false
// to disable button
myButton.isEnabled = false
// to enable clicks
myButton.isClickable = true
// to enable button
myButton.isEnabled = true
WRONG WAY IN LISTENER TO USE VARIABLE INSTEAD OF PARAMETER!!!
btnSend.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
btnSend.setClickable(false);
}
});
RIGHT WAY:
btnSend.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
/** check given view by assertion or cast as u wish */
if(v instance of Button) {
/** cast */
Button button = (Button) v;
/** we can perform some check up */
if(button.getId() == EXPECTED_ID) {
/** disable view */
button.setEnabled(false)
button.setClickable(false);
}
} else {
/** you can for example find desired view by root view */
Button bt = (Button) v.getRootView().findViewById(R.id.btId);
/*check for button */
if(bt!=null) {
/** disable button view */
...
} else {
/** according to #jeroen-bollen remark
* we made assumption that we expected a view
* of type button here in other any case
*/
throw new IllegalArgumentException("Wrong argument: " +
"View passed to method is not a Button type!");
}
}
}
});
EDIT:
In reply to #jeroen-bollen
View.OnClickListener
is Interface definition for a callback to be invoked when a view is clicked.
with method definition
void onClick(View v);
when the view is clicked the View class object makes callback to method onClick() sending as parameter itself, so null view parameter should not occur if it does it's an Assertion Error it could happen for example when View object class was destroyed in meanwhile (for example collected by GC) or method was tampered due to hack
little about instanceof & null
JLS / 15.20.2. Type Comparison Operator instanceof
At run time, the result of the instanceof operator is true
if the value of the RelationalExpression is not null
and the reference could be cast to the ReferenceType
without raising a ClassCastException.
Otherwise the result is false.
three words from the Author
IF U ASK WHY ?
MOSTLY TO AVOID NullPointerException
Little more code will save your time on later bug tracking in your code & reduces the occurrence of abnomalies.
consider following example:
View.OnClickListener listener = new OnClickListener() {
#Override
public void onClick(View v) {
btnSend.setClickable(false);
}
});
btnSend.setOnClickListener(listener)
btnCancel.setOnClickListener(listener)
If you need to disable button add this line of code.
Button button = findViewById(R.id.button)
button.setEnabled(false);
And enable button , just add this line
button.setEnabled(true);
Happy coding :D
first in xml make the button as android:clickable="false"
<Button
android:id="#+id/btn_send"
android:clickable="false"/>
then in your code, inside oncreate() method set the button property as
btn.setClickable(true);
then inside the button click change the code into
btn.setClickable(false);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
btnSend = (Button) findViewById(R.id.btn_send);
btnSend.setClickable(true);
btnSend.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
btnSend.setClickable(false);
}
});
}
You can disable a button from your xml but that won't be dynamic. Best way to disable button dynamically is.
myButton.setEnabled(false);
Just use setEnabled method in Java.
myButton.setEnabled(false);
And in Kotlin
myButton.enabled = false