A simple Android view for drawing.

If you are using Gradle 6.8 or higher version, add it in setting.gradle at the end of repositories:

dependencyResolutionManagement {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

If not, add it in your root build.gradle at the end of repositories:

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.DonghanX:Draw:v1.0.3'
}

• Support multiple types of lines, including solid line, dashed line and Chisel Tip line.
• Eraser, Redo, Undo and ClearAll.
• Change the background of the Canvas by setting image resource or color.
• Keep track of the state after performing drawing actions.
• Save the Canvas as Bitmap.

<com.redhoodhan.draw.DrawView
    android:id="@+id/draw_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<com.redhoodhan.draw.DrawView
    android:id="@+id/draw_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:defaultBrushColor="@color/purple"
    app:defaultBrushSize="20F"
    app:defaultCanvasBackgroundImageRes="@drawable/img_draw_background_1"
    app:defaultEraserSize="15F" />

Note that setting defaultCanvasBackgroundImageRes will override the effect of defaultCanvasBackgroundColor.

• drawViewPressCallback: Invoked when you press the DrawView.
• undoStateCallback / redoStateCallback: Invoked when the content in the DrawView changes. The given receiver parameter returns true if Undo / Redo action is available after the change.

binding.drawView.apply {
    drawViewPressCallback = {
        // Do your stuff here
    }

    undoStateCallback = { isUndoAvailable ->
        // Do your stuff here
    }

    redoStateCallback = { isRedoAvailable ->
        // Do your stuff here
    }
}

binding.drawView.lineType = LineType.SOLID

LineType is utilized by DrawView to modify the path properties and paint options, such as StrokeStyle, Alpha and PathEffect.

binding.drawView.undo()

binding.drawView.redo()

binding.drawView.clearCanvas(needsSaving = true)

If needsSaving is true, then this ClearAll action is capable of being redone.

binding.drawView.canvasBackgroundColor = Color.BLACK

or

binding.drawView.canvasBackgroundColor = ResourcesCompat.getColor(resources, yourColorResId, null)

Note that canvasBackgroundColor receives a single color value in the form 0xAARRGGBB.

binding.drawView.canvasBackgroundImg = yourImageResId

binding.drawView.brushColor = Color.BLACK

or

binding.drawView.brushColor = ResourcesCompat.getColor(resources, yourcolorResId, null)

Note that brushColor receives a single color value in the form 0xAARRGGBB.

binding.drawView.brushSize = 10F

Note that brushSize receives a single float value.
Also note that the minimum stroke width is set to 3F.

binding.drawView.eraserSize = 10F

Note that eraserSize receives a single float value.
Also note that the minimum stroke width is set to 3F.

val bitmap = binding.drawView.saveAsBitmap()

• Inspired by DrawingView in mvojtkovszky.

   Copyright 2022 Donghan X

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.