My question is very simple, I'm trying to dynamically change the width of this button :
<Button>
android:layout_height="35dip"
android:background="#drawable/buttonlesson"
android:text="Level 3 [TAP HERE]"
android:onClick="MenuLI1L3"
android:layout_width="300dp"
android:id="#+id/II3"
</Button>
Here is the code I use :
Button myButton = (Button) findViewById(R.id.II3);
myButton.setWidth(10);
myButton.setText("kl");
Text indeed change but not the width. Sound like there is a bug.
There is another button on its right which suppose to fill the gap when this button is reduced to 10 pixel, so I can't change the LinearLayout above too.
Any explanation & solution ? It should work no? Thanks
I assume wrap_content doesn't work for your in your specific case, right?
If you need absolute width, then you need to assign that via new LayoutParameters, i.e.
myButton.setLayoutParams(new LinearLayout.LayoutParams(
30 * someDensityFactor, LinearLayout.LayoutParams.WRAP_CONTENT
))
where the someDensityFactor is your screen density (float). You also might need to invalidate your layout then as well in order to get the button repainted.
As a suggestion try calling invalidate() on the parent view (which will cause drawing invocations to all the children - including your button). This might not work because what you also need is for the button to re-run its onMeasure() logic (which runs prior to drawing).
Play with either invalidating or any other method which will cause the parent to invoke the onMeasure of the children.
Related
i am getting "Set android:baselineAligned="false" on this element for better performance" while using LinearLayout, I know its regarding performance,but i dont know exactly why it is,please clarify me
If you are looking for a visual explanation like me, then you might find this useful.
When baselineAlign is enabled(i.e if it is set to true), then all the text in that line will be aligned to have the same baseline.
Note: By default, baselineAligned is set to true. (i.e. baselineAligned=true)
When you make baselineAligned=false, all it needs to do is to add new elements to the linear layout and be done with it. The app need not worry about where the baseline of other elements in the layout is.
See the image below for more clarity
android:baselineAligned/setBaselineAligned(boolean): When set to false,
prevents the layout from aligning its children's baselines.
So can take example with linear layout with horizontal child views having multiple TextView with different text size or different views like button there basealignment would be different and you cannot adjust it to have same basealignment if you set it to false
Reference
Update:
By setting android:baselineAligned="false" , you're preventing the extra work your app's layout has to do in order to Align its children's baselines; which can obviously increase the performance. (Less unnecessary operations on UI => Better performance) as mentioned here
I want on the initialization of my activity in android to set the position of some imageView's
by code.
Lets say I have five cards displayed on the screen, all placed in (0,0) by me in the XML.
I want to calculate the screen size (easy to do) and then place the first card at 0.2height , 0.2 width the second one 0.4height, 0.4 width, ETC.
I want to do it through code so i could change some constants in the future and the rest of the changes will apply automatically
Thanks.
Create a LinearLayout container view in your layout, and then use code to add your new View to it
<LinearLayout
android:id="#+id/container"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
And then:
((ViewGroup)findViewById(R.id.container)).addView(myImageView);
try to use "findViewById()" to inflate some parental layouts,
"new ImageView()" to construct new Views and ".add(myImageView)" to add them.
In your code u can use all kinds of setters for the imageview...
(btw: more details would be great, the question is kinda ambiguous)
I've created a custom dialog builder that contains 2 buttons.
Depending on the dialog's setup, I may choose to hide one of the buttons completely, using Window.GONE.
Ideally what I want to happen is:
1. If there is only one button, then fill the layout with it
2. If there are two buttons, then split up the space in the layout equally with these
Is it possible to do this without having to work out the width of the dialog, the number of buttons and then set the sizes manually?
I was hoping there may be a neater way to perform this
ok, here is how I would do it:
<LinearLayout layout_width:fill_parent layout_height:wrap_content>
<Button
layout_width=fill_parent
layout_height=wrap_content
layout_weight=1/>
<Button
layout_width=fill_parent
layout_height=wrap_content
layout_weight=1/>
</LinearLayout>
The trick is to put both elements a width of fill_parent and a weight of 1. If they are both drawn, they will each take up half the screen. If you use View.Gone, one of them will disappear and the other should take up all the space.
yes of cource put your views means button in linear layout and give yor buttons equal layout_weight will solve your problem.
I'm having trouble developing the UI for my first lame "game".
Here is a screenshot.
I'm using a LinearLayout that contains a TableLayout with TableRows. It seems so tedious and hard to control the position of elements.
For example, to get things to line up, I've inserted empty TextViews to "push" other elements into place.
I've also added padding to the buttons to get them to be the size I want.
Is there a better way of doing this?
Thanks!
You definitely want to be using a Relative Layout for this.
You would be able to specify where each button is in relation to other buttons.
Absolutely AVOID developing your UIs the way you are currently trying. The TextViews will be different sizes for different distributions of Android, and will likely only look right on the device you tested them for.
EDIT:
If you need empty space, use the XML attribute android:weightSum="x" in the parent view and android:layout_weight="y" in the child. This will make the child take up (y/x) of the space allotted to it in the layout_height and layout_width.
EDIT:
I think another good bit of advice for this would be to use individual layouts for things like your "direction" buttons. You'll be able to handle where they are on the screen as a group, instead of having to move each individually.
You should use RelativeLayout to solve this problem. I've gone through a similar problem once...
I didn't use the the Android's default buttons, for I had my own images for the pressed and unpressed behaviors...
Let suppose you want to place the east "button". You could use a function like:
public void addEastImageView(RelativeLayout myBackgroundLayout, ImageView center, ImageView east, int leftPadding, int topPadding, int rightPadding, int bottomPadding){
RelativeLayout.LayoutParams rightSide = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
rightSide.addRule(RelativeLayout.RIGHT_OF, center.getId());
east.setPadding(leftPadding, topPadding, rightPadding, bottomPadding);
myBackgroundLayout.addView(east, rightSide);
}
The ImageView called "center" would be the one you called "i" in your image. The padding parameters would allow you to control the distance between the ImageViews. You can create functions like this one to add the "west", "south" and "north" buttons also: you just have to change the parameter "RelativeLayout.RIGHT_OF" to "RelativeLayout.LEFT_OF", "RelativeLayout.BELLOW" and "RelativeLayout.ABOVE" accordingly.
If you want some behavior for your ImageViews, you just have to set it in the setOnClickListener. You can then change your ImageView's "image" with setBackgroundResource, for example, and set the others logic behaviors you want.
Hope it helps :D
Use an AbsoluteLayout - it lets you state exactly where to put every element
http://mobiforge.com/designing/story/understanding-user-interface-android-part-1-layouts
<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<Button
android:layout_width="188px"
android:layout_height="wrap_content"
android:text="Button"
android:layout_x="126px"
android:layout_y="361px"
/>
<Button
android:layout_width="113px"
android:layout_height="wrap_content"
android:text="Button"
android:layout_x="12px"
android:layout_y="361px"
/>
Setting two or more elements of a linear layout the same height seems to be a great problem.
I want to set four buttons in a row to the same height.
android:layout_height="wrap_content" does it for the moment but when the text on one of the buttons is longer than one line this button is increased and therefore bigger than the other ones. Due to different localisations I don't know, when and which button may have a second line.
So my idea is, to set the parent linearlayout to android:layout_height="wrap_content" and all (!) child heights to android:layout_height="fill_parent".
This works (all buttons have the same size), but I'm not sure if this causes any other problems? Because it the parent gets it's height from the childs and vice-versa.
In theory what you are describing should not work ("Because it the parent gets it's height from the childs and vice-versa".) However, we made it work in LinearLayout because it was a very common use case. I recently added similar support to FrameLayout (this feature should be part of Honeycomb.) What you are doing is therefore perfectly valid and will work just fine.
That doesn't make sense :(
Why don't you use android:singleLine="true" and some ellipsode?