Android — Create Bitmap from a View
Tags: android, utility, bitmap, opensource
Published: 2019-03-18 13:41:41

---
title: Android — Create Bitmap from a View
published: true
description: Create bitmap at runtime from the supplied view.
tags: Android, Utility, Bitmap, Open Source
---

![Header](https://thepracticaldev.s3.amazonaws.com/i/mzpopz0td65gv5wkq60y.png)

Hello everyone! This is my first programming tutorial here in which I will discuss about creating the bitmap from a view at runtime.

## Background
I have an [app](https://play.google.com/store/apps/details?id=com.pranavpandey.rotation) for Android in which users can customise all the theme colors according to their requirement. They can also copy or share their theme in the form of a JSON which can be imported to achieve the exactly same look later or can be shared between the other devices. 

Recently, I decided to generate an image from the theme preview which users can share along with the JSON to give some idea about the theme before importing it. The in-app preview already shows the theme before applying it but I wanted to provide the similar kind of functionality for posts shared on social media and in other communities.

## Implementation

### ~~View.getDrawingCache()~~
Initially, I tried to use the view drawing cache. Although, it is working fine but most of the drawing cache related methods are [deprecated](https://developer.android.com/reference/android/view/View.html#getDrawingCache()) in Android 9 (API 28). Please check the deprecated code below:

```java
    /**
     * Creates a bitmap from the supplied view.
     *
     * @param view The view to get the bitmap.
     * @param width The width for the bitmap.
     * @param height The height for the bitmap.
     *
     * @return The bitmap from the supplied drawable.
     */
    public @NonNull static Bitmap createBitmapFromView(@NonNull View view, int width, int height) {
        if (width > 0 && height > 0) {
            view.measure(View.MeasureSpec.makeMeasureSpec(DynamicUnitUtils
                            .convertDpToPixels(width), View.MeasureSpec.EXACTLY),
                    View.MeasureSpec.makeMeasureSpec(DynamicUnitUtils
                            .convertDpToPixels(height), View.MeasureSpec.EXACTLY));
        }

        view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache(true);
        Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
        view.setDrawingCacheEnabled(false);

        return bitmap;
    }
```

### Canvas
As drawing cache API is deprecated, I found that we can achieve the similar result by using the [Canvas](https://developer.android.com/reference/android/graphics/Canvas) API. Please check the new code below:

```java
    /**
     * Creates a bitmap from the supplied view.
     *
     * @param view The view to get the bitmap.
     * @param width The width for the bitmap.
     * @param height The height for the bitmap.
     *
     * @return The bitmap from the supplied drawable.
     */
    public @NonNull static Bitmap createBitmapFromView(@NonNull View view, int width, int height) {
        if (width > 0 && height > 0) {
            view.measure(View.MeasureSpec.makeMeasureSpec(DynamicUnitUtils
                            .convertDpToPixels(width), View.MeasureSpec.EXACTLY),
                    View.MeasureSpec.makeMeasureSpec(DynamicUnitUtils
                            .convertDpToPixels(height), View.MeasureSpec.EXACTLY));
        }
        view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());

        Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(),
                view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        Drawable background = view.getBackground();

        if (background != null) {
            background.draw(canvas);
        }
        view.draw(canvas);

        return bitmap;
    }
```

> Pass `0` for __height__ or __width__ to use the current view dimensions.
> You can check the code for `DynamicUnitUtils.convertDpToPixels(float)` method [here](https://github.com/pranavpandey/dynamic-utils/blob/df2fa843cd1ed0b9fd7c80e236bc99a40d546bba/dynamic-utils/src/main/java/com/pranavpandey/android/dynamic/utils/DynamicUnitUtils.java#L34).


Outputs from both the methods are similar but it is recommended to use the canvas API as the view drawing cache methods may not work in the future releases of Android.

![Output](https://thepracticaldev.s3.amazonaws.com/i/zv2rucou1m04laikj0d4.png)

### PixelCopy
There is another API for Android 7.0 (API 24+) or above devices which you can use to take screenshots of the UI. It seems complicated to me and I have not tried it yet. You can check the official documentation [here](https://developer.android.com/reference/android/view/PixelCopy.html).


## Dynamic Utils

I have created a library for similar kind of utility methods related to color, device, drawable, package, tasks, SDK, etc. which you can use to perform various runtime (dynamic) operations. Please visit the GitHub page for more info.

{% github https://github.com/pranavpandey/dynamic-utils %}

This is my initial attempt on blogging so, I will keep improving the future posts. Please comment to give suggestions and what you want to see in the future posts. Thanks for your time!