Expand clickable area of an ImageView by using padding? - android

I have an ImageView, and I want it to be clickable. The image itself is only 32x32 pixels, but I want the clickable region to be larger so it's easier to hit. I was hoping I could set the layout margin values to increase the size of the imageview's clickable area:
<ImageView
layout_width="32dip"
layout_height="32dip"
layout_margin="20dip" />
That doesn't work, what I could do is just recreate the image resource to have a larger transparent region around it. That's a bit annoying because it's hard to tweak if I ever need to change the clickable region. It's not just a single png either, it's a statelistdrawable so I have to resize 3 different pngs if I ever need to tweak the clickable area.
Anything else I can do?
Thanks

Use padding. layout margins are used if for inserting space outside the boundary of the view.
for equal padding on all sides
<ImageView
android:padding="20dip" />
or to set the padding on each side
<ImageView
android:paddingLeft="10dip"
android:paddingRight="15dip"
android:paddingTop="23dip"
android:paddingBottom="12dip" />
Hope that helps !

Instead of resizing the image (Peter Knego's answer) or increasing padding (Saimon's answer) I suggest to set the minWidth and minHeight attributes in combination with scaleType="center":
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minWidth="40dp"
android:minHeight="40dp"
android:scaleType="center"
android:src="#drawable/your_image" />
That makes sure that small images have at least a size of 40x40dp while the image is not up-scaled if it's smaller. If one day the image is going to be replaced with another image larger than minWidth and minHeight it will not grow larger than 40x40dp as it gets downscaled. Thus a minimum clickable dimension of 40x40dp is always guaranted and the image is always displayed nicely.

Suggestions (never tried it myself):
Create ImageView as large as you want than put image into it without scaling
ImageView.setScaleType(ImageView.ScaleType.CENTER).
Brute force approach: create new larger png that has original image centered and the rest of it is transparent.

Use like below; where width/height is your touch radius
<ImageView
android:id="#+id/editProfile"
android:layout_width="32dp"
android:layout_height="32dp"
android:padding="8dp"
android:background="?attr/selectableItemBackgroundBorderless"
android:src="#drawable/ic_edit"
android:scaleType="fitCenter"
/>
In the above code, I wanted my src size to be viewed as 24dp width/height. And touch radius of 32dp. so I had used padding of 8dp.

Related

keep button drawable image dimensions as original

I created an app where I use Google Books API in it.
As part of the attributions they require, I need to add to each query results the following button:
Now, I wanted to use that Image as a background to a button but I got this results:
As you can see it seems to be stretched with bad quality.
The xml I used is:
<ImageButton
android:id="#+id/tv_Link"
android:layout_width="wrap_content"
android:layout_height="24dp"
android:layout_alignStart="#+id/imagecard"
android:layout_alignEnd="#+id/imagecard"
android:layout_alignBottom="#+id/imagecard"
android:background="#drawable/gbs_preview_button"
android:elevation="50dp"
android:fontFamily="#font/assistant_semibold"
android:gravity="center"
android:textColor="#color/colorLightPurple"
android:textSize="8sp" />
In order to fix it, I decided to use bitmap:
<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
android:gravity="center"
android:src="#drawable/gbs_preview_button"
android:tileMode="disabled"/>
The problem is that it became small like this (good quality, but small):
This dimension is too small since they require the height to be 24dp.
Is there any way I can add this image to the button, to make it 24dp height and still to keep the quality of the image?
Thank you
As you want to hardcode the height to 24dp, then you can also hardcode the width to a value that keeps the aspect ratio of the original image size which is (88 x 31).
So, set the width to 68dp instead of wrap_content

How to show a background image resized into ImageButton size?

I have a multi level LinearLayout to show 4x6 ImageButtons for an advent calendar. But when I want to set the background of the ImageButton, it is too big. How can I set the image background to fit the ImageButton size? I want to show 24 pieces of present boxes in a nice grid.
<ImageButton
android:id="#+id/buttonOne"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:layout_weight="25"
android:background="#drawable/present"
android:fontFamily="#font/christmas"
android:onClick="playOne"
android:text="1"
android:textColor="#android:color/white"
android:textSize="#dimen/button_text_size" />
I think that what you want to do can be done changing/adding 2 things:
Its an ImageButton, so dont use the android:background property, but the android:src with the same drawable
Then add the property android:adjustViewBounds="true" which basically adjusts the image to fit the view while maintaining aspect ratio
I think that should do the trick, else you can also try
Use the android:scaleType property, I would try using fitXY but here are all the possible scale types: https://developer.android.com/reference/android/widget/ImageView.ScaleType
EDIT: Also, you might need to change your width and height properties, either specify a size in dp, use constraints, or wrap your ImageButtons in a GridLayout

How do I make my TextView positioning responsive?

In the image above, the black speech bubble and the red background behind it are a single ImageView that spans the width of a vertical phone screen. The "Hello" is a TextView and the layout is relative. Using margins, I was able to position the "Hello" inside the speech bubble in my Android emulator -- but the positioning is off when I emulate a different phone.
Is there a better way to position my TextView
is there a way to make it responsive (so that the Hello is always in
the speech bubble, no matter what the device)?
Here's my xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/relativeLayout">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/mainGraphic"
android:src="#drawable/finished2"
android:layout_marginBottom="97dp"
android:layout_above="#+id/enterValue"
android:layout_alignParentStart="true" />
<TextView
android:maxWidth="200dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Medium Text"
android:id="#+id/helloText"
android:textColor="#FFFFFF"
android:layout_marginEnd="29dp"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_marginTop="45dp" />
</RelativeLayout>
I would use a FrameLayout instead of the RelativeLayout with same size like the image.
Then use the attributes android:layout_gravity="center" and android:gravity="center" for the TextView.
Try this:
...
<TextView
android:maxWidth="200dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Medium Text"
android:id="#+id/helloText"
android:textColor="#FFFFFF"
android:layout_alignTop="#+id/mainGraphic"
android:layout_alignBottom="#+id/mainGraphic"
android:layout_alignLeft="#+id/mainGraphic"
android:layout_alignRight="#+id/mainGraphic"
android:gravity="center" />
...
Best approach is to use 9-patch image & set it as the background of the Textview. If you use a normal png file, we can't guarantee that it will align correctly on all resolutions & it can become blurred when stretched.
9-Patch image automatically resize to accommodate the contents of the view and the size of the screen. Android SDK provides a tool for creating 9-patch images which is inside SDK sdk/tools directory. See https://developer.android.com/studio/write/draw9patch.html.
You should use a 9-patch for the message shape. What you can do is make the root view of your layout as a FrameLayout and then add a TextView to it. Set the message shape Nine-patch as the background of the TextView.
For creating the 9-patch visit https://romannurik.github.io/AndroidAssetStudio/nine-patches.html by Roman Nurik. There just upload a png file of the image asset and choose the xhdpi definition for best results. The Nine-patch has 3 main properties -
Stretch regions : Defines which areas of the asset can stretch for accommodating different screen densities.
Content Padding : Defines the padding area for the content (text) that is going to appear inside the image.
Optical Bounds : Defines how much area should be optically visible around the asset.
Pros of using Nine-patches :
Scalable
Easy to use
Lightweight
Any amount of content can be put in it.
Hope this helps.
Ideally, you should be using a complete red background to the RelativeLayout, and a black speech 9patch image for the TextView.
But if you really want the RelativeLayout to have background as red with speech bubble, you have to set it at run time.
Calculate the height and width of RelativeLayout at run time say 150px and 300px respectively.
Carefully look at the background image, and determine the edge points of bubble from top, right, bottom and left. For example, if image height is 100px by 200px, and bubble top starts at 30px and bottom ends at 70px, right edge starts at 150px and left ends at 250px. Also calculate the width and height of TextView.
At run time, change the position of TextView based on the above figures.

How to create an ImageView that fills the parent height and displays an Image as big as possible?

I have an ImageView that is defined in the following way:
<ImageView
android:id="#+id/cover_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_below="#id/title"
android:layout_above="#id/divider"
android:adjustViewBounds="true"
android:src="#drawable/image_placeholder"
android:scaleType="fitStart"/>
Now after downloading a new bitmap I change the drawable. The image now appears in the top left corner of the ImageView. Is there a way to have the image fill up the whole height that is possible and then adjust the width of the view to enable scaling the image without changing the ascpect ratio?
The image fills up all the space on a standard screen but on a WVGA Resolution the image takes only about half of the actual height of the ImageView.
If I'm understanding you correctly, what you need to use is the centerCrop scaleType. fitStart scales the image proportionally, but neither the width nor height will exceed the size of the view, and the image will, as you said, have a top|left gravity.
Using centerCrop scales the image proportionally, but causes the shortest edge of the image to match the size of the view, and if there is additional data on the long side that does not fit, it is simply cropped off. The gravity is, of course, center. The below worked for me:
<ImageView
android:src="#drawable/image_placeholder"
android:id="#+id/cover_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="centerCrop"
/>
You can change scale type to fitXY via call to
imageView.setScaleType(ScaleType.FIT_XY);
simply do it in xml like
android:scaleType="fitXY"
Basically the answer here is that there is no predefined value for what you are trying to achieve. The solution is to create a Matrix that fits to your needs and call setImageMatrix(matrix) on your ImageView.

Android image scaling and alignment

I'm trying to show an image scaled while preserving its aspect ratio, but at the same time align it to the bottom.
Using android:scaleType="FitXY" causes the image to be centered vertically and horizontally, so it doesn't get aligned to the bottom.
Using "FitEnd" causes the image to be aligned to the bottom right corner, so it isn't centered horizontally.
Is there any way to get around this? Maybe using some matrix to scale it (scaleType="matrix")?
EDIT: To clarify a bit on what it is I want exactly...
I have an ImageView, whose layout (location, size, gravity, etc.) I can't change. I want to load a bitmap as its source image, but have that bitmap get scaled to the ImageView's size (preserving the aspect ratio of the bitmap) and then aligned to the ImageView's bottom.
EDIT: After trying everything I could think of (and everything that was suggested here), we ended up sub-classing ImageView and doing the scaling/translation ourselves in onDraw.
Try using android:scaleType="centerInside" instead of fitXY.
Layout being used in a Blrfl Labs application to scale an image to fit the area the layout gives it without hosing up the aspect ratio:
<ImageView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="1.0"
android:gravity="center"
android:src="#drawable/blah_blah_blah"
android:scaleType="centerInside"
android:adjustViewBounds="false"
/>
You can use
android:layout_centerHorizontal="true"
android:scaleType="fitEnd"
if your ImageView is inside a RelativeLayout.
Untested, but try adding:
android:layout_gravity="bottom|center_horizontal"
to your ImageView along with FitXY scaling.

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