button interview questions
Top button frequently asked interview questions
I have one text input and one button (see below). How can I use JavaScript to trigger the button's click event when the Enter key is pressed inside the text box?
There is already a different submit button on my current page, so I can't simply make the button a submit button. And, I only want the Enter key to click this specific button if it is pressed from within this one text box, nothing else.
<input type="text" id="txtSearch" />
<input type="button" id="btnSearch" value="Search" onclick="doSomething();" />
Source: (StackOverflow)
I'm trying to create a button that has an image in it and no border - just like the Firefox toolbar buttons before you hover over them and see the full button.
I've tried setting the BorderBrush to Transparent, BorderThickness to 0, and also tried BorderBrush="{x:Null}", but you can still see the outline of the button.
Source: (StackOverflow)
Since there's no button.PerformClick() method in WPF, is there a way to click a WPF button programmatically?
Source: (StackOverflow)
I have a style applied to my whole application:
AndroidManifest.xml:
<application android:theme="@style/ApplicationStyle" android:icon="@drawable/icon" android:label="@string/app_name">
And in my styles.xml:
<style name="ApplicationStyle" parent="android:Theme">
<item name="android:button">@style/CKButton</item>
</style>
<style name="CKButton" parent="android:style/Widget.Button">
<item name="android:textSize">19sp</item>
<item name="android:layout_margin">0dip</item>
<item name="android:background">#ff0000</item>
</style>
But the style doesn't get applied.
I'm sorry if I just used the false name in the ApplicationStyle - Item, but I have no clue where to look for the object names and simply assumed, that android:button applies to all buttons.
Source: (StackOverflow)
I have form with one input for email and two submit buttons to subscribe and unsubscribe from newsletter:
<form action="" method="post">
{{ form_newsletter }}
<input type="submit" name="newsletter_sub" value="Subscribe" />
<input type="submit" name="newsletter_unsub" value="Unsubscribe" />
</form>
I have also class form:
class NewsletterForm(forms.ModelForm):
class Meta:
model = Newsletter
fields = ('email',)
I must write my own clean_email method and I need to know by which button was form submited. But the value of submit buttons aren't in self.cleaned_data dictionary.
Could I get values of buttons otherwise?
Source: (StackOverflow)
I was just checking the design guidelines and wondering about the borderless buttons.
I goggled and tried to find in the source but can't bring it together by myself.
Is this the normal Button widget but you add a custom (Android default) style?
How to make these borderless buttons (of course you can set the background to empty, but then I don't have the divider)?
Here links to the design guidelines:
Source: (StackOverflow)
Twitter Bootstrap's buttons have a nice Loading... state available.
The thing is that it just shows a message like Loading... passed through the data-loading-text attribute like this:
<button type="button" class="btn btn-primary start" id="btnStartUploads"
data-loading-text="@Localization.Uploading">
<i class="icon-upload icon-large"></i>
<span>@Localization.StartUpload</span>
</button>
Looking at Font Awesome, you see that there's now an animated spinner icon.
I tried to integrate that spinner icon when firing an Upload operation like this:
$("#btnStartUploads").button('loading');
$("#btnStartUploads i").removeAttr('class');
$("#btnStartUploads i").addClass('icon-spinner icon-spin icon-large');
but this had no effect at all, that is, I just see the Uploading... text on the button.
Is it possible to add an icon when the button is in the Loading state? Looks like somehow Bootstrap just removes the icon <i class="icon-upload icon-large"></i> inside the button while in the Loading state.
Here's a simple demo that shows the behavior I describe above. As you see when it enters the Loading state the icon just disappears. It reappears right after the time interval.
Source: (StackOverflow)
Before the AppCompat update came out today I was able to change the color of buttons in Android L but not on older versions. After including the new AppCompat update I am unable to change the color for either version, when I do try the button just disappears. Does anyone know how to change the button color?
The following pictures shows what I want to achieve:
The white button is default, the red one is what I want.
This is what I was doing previously to change the color of the buttons in the styles.xml:
<item name="android:colorButtonNormal">insert color here</item>
and to do it dynamically:
button.getBackground().setColorFilter(getResources().getColor(insert color here), PorterDuff.Mode.MULTIPLY);
Also I did change the theme parent from @android:style/Theme.Material.Light.DarkActionBar to Theme.AppCompat.Light.DarkActionBar
Source: (StackOverflow)
In this, this and this thread I tried to find an answer on how to set the margins on a single view. However, I was wondering if there isn't an easier way. I'll explain why I rather wouldn't want to use this approach:
I have a custom Button which extends Button. If the background is set to something else than the default background (by calling either setBackgroundResource(int id) or setBackgroundDrawable(Drawable d)), I want the margins to be 0. If I call this:
public void setBackgroundToDefault() {
backgroundIsDefault = true;
super.setBackgroundResource(android.R.drawable.btn_default);
// Set margins somehow
}
I want the margins to reset to -3dp (I already read here how to convert from pixels to dp, so once I know how to set margins in px, I can manage the conversion myself). But since this is called in the CustomButton class, the parent can vary from LinearLayout to TableLayout, and I'd rather not have him get his parent and check the instanceof that parent. That'll also be quite inperformant, I imagine.
Also, when calling (using LayoutParams) parentLayout.addView(myCustomButton, newParams), I don't know if this adds it to the correct position (haven't tried however), say the middle button of a row of five.
Question: Is there any easier way to set the margin of a single Button programmatically besides using LayoutParams?
Thanks in advance.
EDIT: I know of the LayoutParams way, but I'd like a solution that avoids handling each different container type:
ViewGroup.LayoutParams p = this.getLayoutParams();
if (p instanceof LinearLayout.LayoutParams) {
LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams)p;
if (_default) lp.setMargins(mc.oml, mc.omt, mc.omr, mc.omb);
else lp.setMargins(mc.ml, mc.mt, mc.mr, mc.mb);
this.setLayoutParams(lp);
}
else if (p instanceof RelativeLayout.LayoutParams) {
RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams)p;
if (_default) lp.setMargins(mc.oml, mc.omt, mc.omr, mc.omb);
else lp.setMargins(mc.ml, mc.mt, mc.mr, mc.mb);
this.setLayoutParams(lp);
}
else if (p instanceof TableRow.LayoutParams) {
TableRow.LayoutParams lp = (TableRow.LayoutParams)p;
if (_default) lp.setMargins(mc.oml, mc.omt, mc.omr, mc.omb);
else lp.setMargins(mc.ml, mc.mt, mc.mr, mc.mb);
this.setLayoutParams(lp);
}
}
Because this.getLayoutParams();returns a ViewGroup.LayoutParams, which do not have the attributes topMargin, bottomMargin, leftMargin, rightMargin.
The mc instance you see is just a MarginContainer which contains offset (-3dp) margins and (oml, omr, omt, omb) and the original margins (ml, mr, mt, mb).
Source: (StackOverflow)
Javascript Confirm popup, I want to show Yes, No button instead of OK and Cancel.
I have used this vbscript code:
<script language="javascript">
function window.confirm(str) {
execScript('n = msgbox("' + str + '","4132")', "vbscript");
return (n == 6);
}
</script>
this only works in IE, In FF and Chrome, it doesn't work.
Is there any workround to achieve this in Javascript?
I also want to change the title of popup like in IE 'Windows Internet Explorer' is shown, I want to show here my own application name.
Source: (StackOverflow)
I've a ListView where every element in the list contains a TextView and two different Buttons. Something like this:
ListView
--------------------
[Text]
[Button 1][Button 2]
--------------------
[Text]
[Button 1][Button 2]
--------------------
... (and so on) ...
With this code I can create an OnItemClickListener for the whole item:
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> list, View view, int position, long id) {
Log.i(TAG, "onListItemClick: " + position);
}
}
});
However, I don't want the whole item to be clickable, but only the two buttons of each list element.
So my question is, how do I implement a onClickListener for these two buttons with the following parameters:
int button (which button of the element has been clicked)int position (which is the element in the list on which the button click happened)
Update: I found a solution as described in my answer below. Now I can click/tap the button via the touch screen. However, I can't manually select it with the trackball. It always selects the whole list item and from there goes directly to the next list item ignoring the buttons, even though I set .setFocusable(true) and setClickable(true) for the buttons in getView().
I also added this code to my custom list adapter:
@Override
public boolean areAllItemsEnabled() {
return false;
}
@Override
public boolean isEnabled(int position) {
return false;
}
This causes that no list item is selectable at all any more. But it didn't help in making the nested buttons selectable.
Anyone an idea?
Source: (StackOverflow)
I'd like to have an AlertDialog builder that only has one button that says OK or Done or something, instead of the default yes and no.
Can that be done with the standard AlertDialog, or would I have to use something else?
Source: (StackOverflow)
I have a button as in the following:
<Button
android:text="Submit"
android:id="@+id/Button01"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
</Button>
In my onCreate() event, I am calling Button01 like this:
setContentView(R.layout.main);
View Button01 = this.findViewById(R.id.Button01);
Button01.setOnClickListener(this);
There is a background in the application, and I want to set an opacity on this submit button. How can I set an opacity for this view? Is it something that I can set on the java side, or can I set in the main.xml file?
On the java side I tried Button01.mutate().SetAlpha(100), but it gave me an error.
Source: (StackOverflow)