Trying to use overridePendingTransition to apply custom animations to my activity changes. The problem is that my themed app uses colored backgrounds in the activities, and while animating a black background is visible while one view scales out and another scales in.
I would like to know if it is possible to specify the default background color here, and also if I can make it skinnable.
Any help would be greatly appreciated.
Thanks,
Josh
The animations you supply are only window animations -- they describe how to move the entire window/activity surfaces. There is no concept of a background or other such thing, just 2d transformations (and alpha fades) being applied to the entire window surface.
Further, you need to be careful when creating such animations that when you put them together the two windows are always entirely covering the screen, because there is nothing behind your application to provide a background. Thus any such animation typically needs to involve one of the windows remaining opaque if another is fading, and if they are moving they need to do so in a way that the always cover the screen as it done with the default slide left/right animation.
Related
I'm tackling the task of an overlaying drawable over a view that animates the drawing of a checkmark as in the following video https://vid.me/MsQj
I don't have a preferred method for doing this but it's just not coming out the way I wanted it to, I tried:
Two views, each with on side of the checkmark to be revealed with an animation, however I'm stuck at the "revealed with an animation" since I can't use the circular reveal on -21
Frame by frame animation, this is the easiest but I'd hate to have 60 images for this stupid animation if it can be done programmatically
Drawing on a custom view canvas
My question would be, is there anything that can make this easier on me, or do I have to tackle it head first and just get on with it
You could create a custom View class which contains two lines defined by ShapeDrawables, one for each leg of the tick. Expose the lengths of these two lines as properties of the class, and then use Property Animation to animate the lengths of the lines.
Property Animation is flexible enough to handle pretty complex timing and sequencing of various properties. In this particular case you would probably want to use an AnimatorSet to sequence the two line animations so the second starts once the first has finished.
I ended up developing a custom View thanks to #SoundConception suggestion and finding out about ObjectAnimator which are very powerful in Android. In essence what goes on is we set a width for the first and second line that make the checkmark and using the animator change the value of those properties from 0 to the desired one.
On the setter for the property, we invalidate the View to redraw it with the new value and with a little tweaking I made a nice View that while its currently only working for my specific layout (ie it needs some more work on the offset calculation) it's able to draw an animated checkmark with some stuff that is customizable.
Precisely, you can set the line width, the color, the length and the animation time. And touching the java file, you can change the interpolator and all the rest of the stuff.
Hopefully the code, while not really commented serves as a basis for someone trying something similar.
For example the following code would generate something like this video, although not really because I was testing opacity and thinner lines, but you get my drift.
<coop.devtopia.CheckmarkView
android:layout_width="250dp"
android:layout_height="250dp"
android:layout_centerInParent="true"
android:id="#+id/view"
app:first_leg_length="50"
app:second_leg_length="100"
app:total_duration="1500"
app:stroke_width="20"
app:stroke_color="#22000000"/>
Repository
Update 4/2/15
I've played with this a little further and added dynamic offset calculation (fancy way of saying centering) to the tick, meaning we can generate big checkmarks, small checkmarks, skinny or thick, reversed or straight and they will be centered in the view. Can't guarantee the same for checkmarks bigger than the container, they will likely be cropped.
Here are a few of the checkmarks generated for this demonstration, of course the animate as if drawn and the effect can be very pleasing and resource friendly. This turn out to be a pretty interesting subject after all.
Is it possible to rotate views in XML with APIs previous to Honeycomb - maybe with the support package? Or is the only way to create a custom class, like described here Vertical (rotated) label in Android
Edit: What I need is a statically rotated view (specifically a TextView, but I guess it's enough to know how to do it with a View). Starting with honeycomb there's a rotation attribute which can be used in XML. I need something like that.
The only thing I have found until now is use an animation with duration 0 but this still moves a bit at start and I don't want that. I tried setting the views invisible and attaching a listener to the animation which makes them visible on animation finished callback, but that made strange results... that changed the position of the views, for some reason.
The best way is with the custom subclass implementation that you linked to, where you can rotate the canvas and resize the view appropriately. This ensures that the view bounds are also set to match the text that is drawn.
The only method of transforming views externally prior to HC is the animation framework, and applying an Animation to the view with a duration of 0 and fillAfter set to true will work, but you may notice flickering on some devices as often the view will render normally on its first frame and then animated to its final position from that point onward. You can work around this by hiding the view and displaying it a bit late...but you can see how hacks are starting to stack up.
In addition, doing an Animation prior to HC will not transform the view bounds themselves, so you won't be able to neatly pack other views around this one because its position from a layout perspective will still be the rectangle calculated for the horizontal (non-rotated) text.
The simple subclass is definitely the preferred method.
HTH
Is it possible to rotate views in XML with APIs previous to Honeycomb
There is RotateAnimation. However, depending on what you are trying to accomplish, that may not meet your needs.
I am working on a project that involves painting on images.
To delete the unwanted lines or curves i have to draw a border and X button to delete it.
I have a relative layout where i have the freehand drawing canvas. on edit mode i should make them as u see in the pic, where i have to create button on a varying x,y positions.
i am confused how to achieve this.
Thanks in advance.
Jana.
I suggest doing this manually rather than using the Button widget. Override the onTouchEvent on the view holding your painting and use MotionEvent.getX and MotionEvent.getY in combination with MotionEvent.getAction to determine behaviour when the user touches the 'button'. Skipping widget creation will improve performance and open up doors to other types of functionality.
You could use the deprecated AbsoluteLayout container for this or keep the RelativeLayout and use layoutMargins to set the location of the buttons. The former is the route you should take despite the container being deprecated as the later breaks the layout paradigm by misusing margins...
You should keep in mind that there are a variety of devices with different screen sizes and setting explicit, pixel based locations is going to be awkward.
I currently have an app with a regular layout of buttons and widgets. On top of this I'd like to draw some animated sparks and particles and whatnot going on in response to events, so I've got it in a FrameLayout with another View on top to draw the animations. The problem is I can't work out a way of getting smooth movement out of it. I've tried a few options:
SurfaceView: because of the way it takes over the screen, you can't see anything behind a SurfaceView so the background is fully black.
Override View.onDraw and call invalidate(): this almost works, but invalidate isn't a very reliable way of getting a redraw to happen soon, so the motion is very jerky.
Animation framework: Testing with TranslateAnimation, it seems a bit smoother than using onDraw(), but animations are designed to run for a specific duration and I want to draw indefinitely.
Anybody know any tricks to make one of these work properly, or something completely different?
I'm working on a game that in some ways is similar to Tetris (imagine a 2D array of colored squares that sometimes move around)
I am trying to animate the individual squares so they will smoothly slide down from coordinate to the next. Since I wanted to use Android's built-in tweening feature, the animation has to apply to the whole View (rather than parts of it). This doesn't work well for me because I only want some of the colored squares to slide down, and the rest of them to stay still.
The (theoretical) solution I came up with to resolve this is to make 2 Views, layered directly on top of each other. The top view is for animating squares when they need to move, and the bottom layer is for the static squares. The animation-layer is transparent until I am ready to animate something. I then simply turn on the colored square in the animation-layer, tween it to the new location, and turn it back off when done. In the same time span, the static-layer just turns squares on and off at the right time to make the whole thing look seamless to the end user.
The proposed solution is just a theory, since I haven't been able to make it work correctly yet. Since I have been having trouble, I was wondering if this is even the best way to solve the problem? Perhaps there is a more elegant solution that I am over looking? Anyone know of a better way?
If you just want to animate a single element check out the namespace android.view.animation.Animation. You can also use Drawable shapes and draw them directly. Finally, if you want a simulation then you will have to look into threading. Basically you will create a timer to update the canvas for you based on an interval. There are some other view canvases you can use as well like the GLView canvas.