Right way to do scrollable view of custom buttons? - android

I've just started playing with Android in the last few days and have begun to put together a simple application. I am struggling to work out whether I'm doing things the "right" way or just making life difficult for myself.
The app displays a series of connected nodes on the screen, similar to a mind-map. I want to be able to tap the nodes in order to edit them. When the map of nodes becomes larger than the screen, I need to be able to scroll on both X and Y axes as needed to see the whole map. Image of current implementation at http://ubergeek.org.uk/images/nodetest.png.
Currently I don't have scrolling working, however I assume that I can do that by making the root view a ScrollView and sticking an AbsoluteLayout inside that (though it's deprecated, I wish to place objects at specific X/Y coordinates).
The nodes themselves are currently each a pair of roundrects (one for the outline and one for the fill) and a drawText and are being drawn in the main activity's onDraw(). In order to make these clickable buttons I believe I need to create a custom view for the button in order to use its onClick() events. I can then create a view object for each of my nodes and add them to the AbsoluteLayout view.
Does this sound like a reasonable way to do it in Android, or is this a horrible abuse of the API? :)
Thanks!

Nope, that sounds about right. You just need to make sure that the view contained by the ScrollView has the right dimensions so the scrollbars will show up right, but I'm sure you got that covered.
It's certainly a bit non-standard, but I'm tempted to say that your approach will work right... I'd even go so far as to say that it's not a hack. Please keep us posted on how it works out, and if anything breaks!
(Btw, the SDK mentions that you should write your own layout instead of using AbsoluteLayout. Personally, I'd say use the AbsoluteLayout.)

Related

List with views stacked on top of each other

You usually traverse a list by scrolling through the views that are placed one after another. What I'm trying to achieve is similar, but the views would be stacked on top of each other. The views will also cover the whole screen. So when you scroll, the top view slides away (or uses some other transition animation), but the bottom one is not moving underneath. You can imagine that the views are like the papers in a top spiral-bound notebook.
So my question is - does something similar already exist? I haven't been able to found anything so I might need to make a custom implementation. Oh and the views will each contain an image and there might be quite a few of them, so it will need to handle that (I was thinking of using Android Universal Image Loader). Thanks.
Sounds like you want to use Depth page transformer, via http://developer.android.com/training/animation/screen-slide.html#pagetransformer

Putting a button on top of an imageView

So here is my problem. I've spent couple of days on this and didn't get anywhere. I've tried every layout possible, but it just doesn't seem to work.
Basically, I have a map of a floor and I want to make it so when you click on different parts of that floor, a new activity or a dialog box shows up. I want this to scale for all the devices. Why is this so difficult in Android? I would think that putting buttons on top of an image would be easy and made sure that it wouldn't move like in HTML.
I have been looking into Surface View, but wasn't sure if that's the best way to go? I can get the coordinates of the objects on the floor, would that help?
I want to implement this inside of an fragment. Thanks!
One possible solution could be to have a RelativeLayout as the base layout of your 'Floor Map' fragment, with the floor image set as its background.
Then you could add buttons or any other views to the Relativelayout at the coordinates of the objects.
If you already know how many features the floor will have, you could add the buttons statically, otherwise, loop through your array of features to add them dynamically.

iOS: Relative Positioning like Android's layouts

Is there any way position views relative to each other like you can with Android layouts?
Example: You have two UILabels that are dynamically set to strings of variable length, one above the other, and you want the bottom label to appear directly below the last line of the top label, regardless of how many lines the top label ends up having.
Another example: Same situation as above, but one of the labels is sometimes hidden. You want the resulting label(s) to be centered vertically in the parent, regardless of whether it's one label or two labels.
Android's Linear Layout and Relative Layout make this very easy to do, but I can't figure out how to do this is iOS. Can it be done?
You will be able to do this using AutoLayout in iOS6. For an application that should run in iOS before 6.0, you have to do it by yourself, but this is not very complicated.
Actually I have implemented a class to do this (that's a long time ago, I hope it still works, but there is no reason not to). This OHStackView class is a subclass of UIView that automatically layout its subviews horizontally or vertically to stack or align them.
You can ask OHStackView to stack its subviews horizontally or vertically (one above the other, etc), or align their top/bottom/left/right borders or their centers, and even specify a padding between each subviews. Each time one of the subview changes its frame or size, OHStackView will automatically relayout all depending views to realign everything.
(E.g with your two UILabels, a simple call to sizeToFit on your labels to make them adjust their size to their content will relayout everything around automagically)
There is an example project provided so feel free to test it.
Note: IIRC, my subclass does not take the "hidden" property of the subviews into account. But you can easily add support to this behavior by adding a condition like if (v.hidden) continue; in the for loop of its layoutSubview implementation to only take non-hidden views into account in the layout algorithm.
HTH
I've been searching if it's possible for a long time. As far as i can tell, it's not possible for now. I don't remember where i read this,but it will be possible with ios6. Instead of using Android's Linear Layout,you can use sizeWithFont method to detect size of your UILabel,then you can set their frame to position them.First,you need to set their text of course to find their size according to their font family. Another thing you can use is sizeToFit method. Unfortunately,i don't know how to use it. You can give a shot,though. At that time,i found this.Maybe ,you can use it https://github.com/scalessec/CSLinearLayoutView

Flip View like in Contacts Activity (ICS) or Google+ App

I am searching for an easy way to implement a view flipping like used in several occasions by google apps.
Behaviour should be like this: OnScroll the view should move to the side and show the content of the next page. If scrolled far enough the view should move smoothly into position (after lifting your finger) and snap into place. If not scrolled far enough and the finger is lifted, the original view should smoothly move to the original view and snap into place.
I search around and didn't figure out a easy way.
So I though about something like this:
Hide the ScrollBars of the horizontal ScrollView.
Set the scrollView position manually according to the position I get from a GestureDetector.
I am pretty sure that this way works. But it seems to complicated to me, because there are to many things that have to be programmed. Like the animation (Smooth acceleration, deceleration, snap), Gesture, calculation of the actual position....
So my Question: Am I on the right way or is there an easier approach? Did I miss something during I searched for a solution? Is this function already implemented by android or does it really have to be done by myself?
Look for this tutorial. Also if you try to search here, on SO, you will find thousands of similar question with lots of different solutions. You can choose one, that will useful for you.

Problem with Android drag - drop UI development

I am newbie to android so this might be one of the dumbest question you face.
I am developing UI in Eclipse through drag-drop.I have added many elements in one screen now
the window where you drag-drop UI elements is not growing/scrolling beyond a capacity.
So I am not able to see newly added elements.
Please check image for more details..
You can observe elements after Storage Position are not visible.
How to check other elements or cant we add elements beyond a certain number/size ?
~Ajinkya.
You can add as many elements as you want. I can see a bunch of LinerLayouts for each of your items, but each linear layout is one row and has a horizontal orientation, correct? I'm not sure what you have as your overlying view, but make sure that all of those items are inside of a LinearLayout with vertical orientation. You can wrap that in a <ScrollView> to add a scrollbar to it. Here is a Scrollview example
Side note: Also, the drag and drop is nice to look at, but I've always had a better experience directly editing the xml, even if I started creating the layout with the GUI. It's easier to tell what is going on with each element and make changes. It's best to check the way everything looks in the emulator too, sometimes it can look different than in the GUI editor, especially if items are put into your interface programmatically.

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