FloatingActionButton with text instead of image

Question

I\'m trying to figure out how can be modified FloatingActionButton from android support library. Can it be used with the text instead of image?

Something like this o

Answer 1

I used a CardView to achieve the same result

  <androidx.cardview.widget.CardView
            android:layout_width="@dimen/dp80"
            android:layout_height="@dimen/dp80"
            android:layout_gravity="center_horizontal"
            app:cardElevation="@dimen/dp8"
            android:layout_marginBottom="@dimen/dp16"
            android:layout_marginTop="@dimen/dp8"
            app:cardBackgroundColor="@color/colorWhite100"
            app:cardCornerRadius="@dimen/dp40">

            <TextView
                style="@style/TextAppearance.MaterialComponents.Headline4"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_gravity="center_horizontal"
                android:background="@drawable/shape_go_bg"
                android:text="GO"
                android:gravity="center"
                android:textColor="@color/colorWhite100" />
        </androidx.cardview.widget.CardView>

Answer 2

Answer of @NandanKumarSingh https://stackoverflow.com/a/39965170/5279156 works but i have made some changes with fab in code (not xml because they will be overwritten in class methods)

fab.setTextBitmap("ANDROID", 100f, Color.WHITE)
fab.scaleType = ImageView.ScaleType.CENTER
fab.adjustViewBounds = false

Where setTextBitmap is an extension for ImageView class with similar functionality but it supports multilne text

fun ImageView.setTextBitmap(text: String, textSize: Float, textColor: Int) {
    val paint = Paint(Paint.ANTI_ALIAS_FLAG)
    paint.textSize = textSize
    paint.color = textColor
    paint.textAlign = Paint.Align.LEFT
    val lines = text.split("\n")
    var maxWidth = 0
    for (line in lines) {
        val width = paint.measureText(line).toInt()
        if (width > maxWidth) {
            maxWidth = width
        }
    }
    val height = paint.descent() - paint.ascent()
    val bitmap = Bitmap.createBitmap(maxWidth, height.toInt() * lines.size, Bitmap.Config.ARGB_8888)
    val canvas = Canvas(bitmap)
    var y = - paint.ascent()
    for (line in lines) {
        canvas.drawText(line, 0f, y, paint)
        y += height
    }
    setImageBitmap(bitmap)
}

Answer 3

convert a text into bitmap and use it. its super easy.

fab.setImageBitmap(textAsBitmap("OK", 40, Color.WHITE));

//method to convert your text to image
public static Bitmap textAsBitmap(String text, float textSize, int textColor) {
    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    paint.setTextSize(textSize);
    paint.setColor(textColor);
    paint.setTextAlign(Paint.Align.LEFT);
    float baseline = -paint.ascent(); // ascent() is negative
    int width = (int) (paint.measureText(text) + 0.0f); // round
    int height = (int) (baseline + paint.descent() + 0.0f);
    Bitmap image = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(image);
    canvas.drawText(text, 0, baseline, paint);
    return image;
}

Answer 4

A very little modification to comrade 's answer to support it for android API below 21 just add app:elevation="0dp" to the FloatingActionButton

This might help others!

Answer 5

FABs are usually used in CoordinatorLayouts. You can use this:

<android.support.design.widget.CoordinatorLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto">

    <android.support.design.widget.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|end"
            android:layout_margin="@dimen/fab_margin"               
            app:backgroundTint="@color/colorPrimary" />

      <TextView android:layout_height="wrap_content"
              android:layout_width="wrap_content"
              android:text="OK"
              android:elevation="6dp"
              android:textSize="18dp"
              android:textColor="#fff"
              app:layout_anchor="@id/fab"
              app:layout_anchorGravity="center"/>

</android.support.design.widget.CoordinatorLayout>

This is what does the work

app:layout_anchor="@id/fab"
app:layout_anchorGravity="center"

Result:

If you're using some layout_behavior for your FAB, you'll have to make a similar layout_behavior for the TextView

Answer 6

You can't set text for FloatingActionButton from the support library, but what you can do, is create a text image directly from android studio : File -> New -> Image Asset, and then use it for your button.

In the terms of Material Design; they didn't mention using text with FloatingActionButton, and I don't see any reason for doing that since you don't really have much space for a text.