Android: How to change layout in code - android

I have basic knowledge of layouts and so far in my applications I always had one static layout for each Activity. Now Im trying to create a single Activity with a basic framework (Title, some buttons) and a Layout I need to change after clicking a specified button.
Example:
I have a Title bar, a Linear Layout under it and 3 buttons under it. After clicking one of the 3 buttons I change the title text and the button appearance. But I also need to change my Linear Layout between Title bar and buttons. I didnt know how to do this exactly, so I made it Linear Layout in my main.xml, but after clicking one button, I actualy need it to be a Table Layout (or a List View), after clicking another button I need it to be a Relative layout. I hope you get the picture. In all cases I need to add some elements into it (table rows, some views etc.)
My question is, what is the best way to acomplish this? Thanks!

Related

Android Views using Templates

I've got multiple screens in my applications, which are nearly the same:
Basically there's a heading on the top and a view at the bottom including buttons. If I click on a button, the text of the heading should change. Then, when clicked on determined buttons, there should appear a second header, under the first one, in some cases a third. Each of them includes buttons. When clicking on a button of the second header, the third header should change, when clicking on the third header, only the content below the headers should change.
My target is also to nest (3) different templates, but to define each of them only for once (in xml). Is there a way to do this?
Don't know, if the image works, here's the link to dropbox.
Your main layout should be 3rd template layout.
You just have to hide the buttons or the button layout using attribute setvisibility="gone" in xml layout and in java when you click the button you can set visiblity to visible and you can also do set text to textview to change the header text to whatever you want on click of the buttons.
Hope this helps you
One solution is to declare different xml Views, which could be included by using the 'include' tag in other xml files.

Conditional widget visibility in layout XML

I'd just like to ask if it's possible for widgets to have conditional visibility within the layout XML?
Specifically, I have 2 layouts that each have a ListView. I've also implemented a custom layout for the list items.
The custom list item layout has 3 buttons, however, for one of the activities, one of the buttons isn't relevant and must be removed/hidden.
Is it possible to accomplish this in the layout XML? I'd really rather not create another custom list item layout just to remove one button for one activity.
Thanks in advance.
Put in activity a button.setVisibility(View.GONE);

Custom buttons arangement in Android

I'm trying to build an Android app where I would like to display some Buttons in various places, as in the demo image attached.
The challenge here is creating the custom buttons and arranging them.
As for the custom Buttons, I guess I could achieve that using CustomViews or a simple button with a Custom Drawable as Background.
Are these the right points to start, any other ideas?
On arranging them, I have no clue how to achieve that.
As Android_Crazy and Closeratio have already said, a RelativeLayout is the most suitable option for custom placement of buttons in general. However, for the exact placement of buttons pictured in your example, a LinearLayout would work just fine.
In a LinearLayout you may place views under or above eachother (with android:orientation = "vertical", relevant for your example) or next to each other (android:orientation = "horizontal"). You can also add margin to your views to alter the horizontal position (layout_marginLeft or layout_marginRight) or the vertical position (layout_marginTop or layout_marginBottom).
As for the buttons' appearance, I always use custom background drawables, usually with a custom xml to add a different drawable for when the button is being pressed or selected.

Android: Dynamically vary number of buttons in a custom View

I am learning Android by implementing a clone of Mastermind. I want to break up the screen (or View) into three parts: the board with the users guesses so far and feedback, a series of control buttons, and a series of buttons to pick the color of the next peg.
My instinct is to do this is a modular way. The layout files uses nested LinearLayouts (I know not the most efficient thing to do, but this is an educational experience.)
The "board" is a custom View where I do a lot of drawing with a Canvas. The buttons on the bottom are declared in the layout file. Notice the orange strip to the right?
Right now that is another custom View. I want to add a variable number of buttons to that custom View based on the number of colors the player can choose from. A button press would select the color for the next peg in the player's guess. (There are 3 versions of the game, easy, medium, and hard each with a different number of colors.)
So, how do I add a variable number of buttons to the custom View I am creating? Or am I approaching this in the wrong way? Should I use a prebuilt layout? If so, which one and how could I dynamically change the number of buttons in the layout?
Thanks for any help. Cheers!
You can do this in two ways:
Using a predefined layout and setting initially the property
"visibility" of all the buttons to "gone", then programatically you
can set the "visibility" of the buttons you need to "visible". The
"gone" property makes the button invisible and also not consumes
space in the layout.
Adding dinamically buttons to the main layout, first you will have to
create or "inflate" them.
The second options is more powerful, but also more difficult if you are learning.

Hiding and showing android layouts - How do you mark active layout?

I'm just writing my first android app and in one layout xml file I have four buttons that will display a different layout when pressed. Instead of creating four seperate screens, I've just put the four layouts in the same layout as the buttons with android:visibility="GONE", and then when a button is pressed, I set it's corresponding layout to being visible.
My question is, is there a best practice or suggested method for keeping track of the active layout so that when a button is pressed you can set the active layout back to visibility="GONE" before making the new one visible. I thought I could just set a string value with the ID of the active layout, but then findViewById wont take the string to get a hold of the layout. Any help or suggestions would be great. Thanks!
Why do you use a string to save the ID of the layout? Can you not just use an int since the ID's are such? Or set the visibility of the layouts from the onClickListener you attached to each button?

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