I am wondering what would be the best practice for android. To draw or to load an image?
For example I want to have a circle that is green filled with the text 25 in it.
-Should I have it in .PNG image file and just load it to the imageview placeholder when I need it?
OR should I load it in Java (by determining the position in java and load it from my res folder)?
OR Should I draw it (draw a circle, fill color, add text field inside)?
On another note, to have a checkmark, what do advise me to do?I don't even know how to draw that
I really need your help in this
Thank you so much
I'd actually argue that there is a single right answer. You should use a shape with a set color and text view inside it. It is easy to do what you've described in xml, see: Oval Gradient in Android for an example (there are a number if you google for android shapes). This will be less CPU/memory intensive than loading a bitmap, and more importantly, it will work for and look good on every screen size. As an added bonus of the user has changed their default font sizes, a textView/shape can respect that and a static image can not. Just set the background of your TextView to be the shape drawable (either in xml or programatically).
To get a bitmap to look good on multiple devices (a must for android development) , you will need a number of different versions of the same bitmap at different resolutions (XHDPI, HDPI, MDPI... etc).
Check marks are harder because they don't conform to a standard shape. Those you probably will have to make pngs for.
It depends on what you want to do.
Rendering a bitmap will be faster, but you cannot manipulate it after it is drawn.
So, for your case, you have a green circle with 25 written it. Do you also need a green ball with 23 and another with 24 in it? What about other colors?
It really depends on the amount of variation you need. At a certain point the overhead of using dozens of images will not be worth the evert of drawing to a canvas. Or, depending on how complex the images are, it will be.
The question is not "Which is better?", but instead, "Which is better for what I need to do?"
I'm not an expert on Android development but after seeing your question I have done a bit of reading and came across this article on displaying images with android that is relevant and includes some code to possibly help you out. http://www.javacodegeeks.com/2011/07/android-game-development-displaying.html
As for your image of a check mark, why dont you just go into photoshop or paint and use the line tool to draw a checkmark and then fill it in with color and save it as a .png perhaps?
Related
I have an image in my assets folder on which I am drawing stuff using an external program and then using them in my app. The problem is that the bitmaps are blank (transparent) with black and white objects in them. Note that the objects are created with Anti-Aliasing on to look better. I know this was asked before but I couldn't find what I want. I need to replace all the black and white pixels in the image (even the transparent anti-aliased ones!) to the colors given by the user. Below are some images to show what I want to do:
Please note that this is just an example and I have even some very complicated shapes and the final colors aren't known (as inputed by the user in RGB style).
Any help is appreciated. Thanks! :)
Usually you can tint the images you load apliying them a color at runtime.
The problem is that color applies to the whole image and it only matchs exactly the same color in white pixels, with or without alpha.
So you could separate all the areas of the image with the same color, save them as white and then tint them at runtime while overlapping one over another.
It depends on the framework you are using.
I am learning about Android UI and am unclear why people use nine-patch, when you could use vector graphics, because those are scalable without any pixel degradation. I am a beginner in Android, so I hope I am not missing anything here, but it seems like it would be easier to build vector graphics and use those. You would not need the special editor to build them.
Can anyone explain the advantages to using nine-patch over vector? (Don't just explain advantages of nine-patch, as that is already done on StackO., but rather the advantages that vector does not have). Because it seems like Android recommends nine-patch. Thanks.
In vector graphics all side are scale or stretch when we set it to any background whereas in 9-patch we can define which sides can scale or strech so at runtime only those side scale which we set it to scale in 9-patch tool.
from this
-> The advantage of using 9-patch images is that when using it as a background, for instance, the image won't stretch and loose proportions in different screen sizes. the center 'patch' will remain as is and the 'borders' patches will be stretched to fit the screen/view size.
let say you have this image.
and a button with fill parent width. if you set this image to button background it will scale completely and your image gets blur (mean t will expand to button width)and it will not look good. so what 9 - path tool do that you define that online scale some part of image let say if width is fill parent. dont scale whole image . let say we set that after t (in image). scale whole area, so t will not get blur. so this will make good your button.hope you got my point..:)
after making your image 9 patch and setting to button background. your button look like this.
instead of t(in image). whole area expand and fill the buttons width.
Imagine a button with rounded corners. How do you scale it? If you scale it only horizontally, you will have elliptic corners, which would be ugly.
This is what 9-patch is for.
i hate 9patches. i am quite attentive when doing my artwork. i don't even use photoshop. i go with illustrator.
i do everything right when exporting my artwork, i used to do my 9 patches with insane zoom on, maybe check afther that in photoshop for misplaced pixels...
** sad trumpet ** when put on a view, if i used some subtle round corners like 6px or 10px and a stroke everything looks awful at mdpi.
So I solved my problems by marrying the two. I wrote my own 9patch which uses vectors. :)
Everything looks like it's been touched by baby Jesus. Perfect corners, strokes and, best of all, you can use one asset for all the screen sizes, densities while, of course, no more transparent borders, wicked errors because 9patch won't stretch inward, so on and so forth.
I use vectors for icons too. While there sometimes are issues with various effects, these are minimal and easily avoided if you do some reading on how to avoid them.
Best of luck to all you guys!
This is a very basic example.
You can do whatever strikes your fancy. Because of the performance impact of svg's on an app, when first run [or when the user changes appearance options, i like to save the newly generated bitmaps as pngs, if possible.
You don't get any more "best of both worlds" than this.
You can define content are on a 9-patch image which means (for example) text will always be placed in that specific area, I think you cannot do this in Vector image. Android has built-in support for 9-path but for vectors you have to use a library.
9-patch rendering is easy to implement and efficient. If you have an image that can be scaled by stretching horizontal or vertical lines (e.g. buttons or rectangular icons), then use a 9-patch. If you have some icons that don't scale well, then create multiple versions at different resolutions and use Android's resource management to handle it. Both of these approaches are much easier and more efficient than vector graphics.
If you have large images or scenes to render, and you don't want to take up a ton of space with bitmaps, thats when you start thinking about vector graphics.
I need to put together a complete image, as seen here. Each piece of the segmented tree is an individual image, but I am unsure about how I should put the pieces together efficiently with spacing in between. I've thought about stacking the images on top of each other one at a time within a canvas, but I have my doubts as to whether this is the approach that I should take. Is there a different type of container I should use or a better method of accomplishing the same task?
EDIT: just to clarify, I need to assemble the image programmatically, beginning with the base segment and eventually ending with the top segment.
If you use a program like Gimp, you can added each image as a layer, then move the layers around correctly. I'm not quite sure how you want to represent the space between the segments, transparent?
Any way after you have your image assembled the way you want you can either merge the layers or save it to a format that will flatten out your images.
I'm not sure if you want your image to be able to stretch at all or not. If so, you can save it as a .png file and then use draw9patch or equivalent to add in stretching segments. Also I'm not sure if you have to support multiple drawable sizes, if so I have a free Android app, DP Image Calculator on Google Play that might help. Just remember start with the highest resolution and work you way down to the smallest.
Hope this helps. If you have more question let me know. Have a great day.
I have quite a few buttons in my application, they vary in sizes based on the text inside. I want to customize the buttons but I am not sure if I should use
A) Ninepatch pngs
B) Android xml created
C) Photoshop pngs
I want the buttons to scale nicely and therefore not look distorted based on screen size. What are the positives and negatives of the above methods? Is there an ideal way to go about this?
It depends on what they should look like. Rounded corners? Complicated images? Drop shadows? Plain colors?
If you want simple buttons that are monotone in color, xml drawables are the best solution. You can do rounded corners through xml, so if plain is what you are looking for this is the best option.
If you are working with an image, then a 9 patch is the way to go. Play around with the draw9patch tool that comes with the sdk to get the hang of it. You also don't necessarily only need to leave the corners in tack, sometimes you may want to break up the resizable area depending on the image.
PNGs are the last resort as they are the least flexible of the 3 options.
By the way, you should also consider using a state list for all of your buttons, regardless of how you implement the drawable that the button uses. See the link below:
http://developer.android.com/guide/topics/resources/drawable-resource.html#StateList
iam stuck with the creation of a nine patch for a progressbar background.
It has a repeating pattern like a ruler-scala and that given me headache.
here is a image of what i want(at the bottom) and what i have (top).
can someone give me a hint how to acomplish my goal?
edit: or is it generelly possible to do this with a 9patch?
my other attempt was to make a with android:tileMode="repeat" but there i get problems with the height of my image (repeating in the second line), i need something like repeat-x.
Thanks in advance
edit2: ok i managed to do my repeating 9patch by stretching the whole repeating pattern, but its not ideal :(
You seem to be overestimating the power of 9-patches. The most you could do is have a ruler image with expanding space between the ticks. You can't, however, make a 9-patch that automatically tiles parts of your image.
On the other hand, if you create a BitmapDrawable programatically, you can set the tile mode separately for the X and Y axes.
I used to do this in my webview project using border image which provides both options (repeat, stretch, fill).
As webview has kind of it's own problems in android (mostly fixed element) I decided to be more android for the next project and I found out that it's not possible to have the repeated border using 9Patch. It's so awkward as it's needy but not implemented.
In a word android development area makes me crazy, one option here one option there is a usual thing here.