Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
// Use of this source code is governed by a BSD-style license that can be

import android.graphics.Color;

public class Main {
    private static final float LIGHTNESS_OPAQUE_BOX_THRESHOLD = 0.82f;
    private static final float LOCATION_BAR_TRANSPARENT_BACKGROUND_ALPHA = 0.2f;

    /**
     * @return The base color for the textbox given a toolbar background color.
     */
    public static int getTextBoxColorForToolbarBackground(int color) {
        if (shouldUseOpaqueTextboxBackground(color))
            return Color.WHITE;
        return getColorWithOverlay(Color.WHITE, color, LOCATION_BAR_TRANSPARENT_BACKGROUND_ALPHA);
    }

    /**
     * Check which version of the textbox background should be used depending on the given
     * color.
     * @param color The color value we are querying for.
     * @return Whether the transparent version of the background should be used.
     */
    public static boolean shouldUseOpaqueTextboxBackground(int color) {
        return getLightnessForColor(color) > LIGHTNESS_OPAQUE_BOX_THRESHOLD;
    }

    private static int getColorWithOverlay(int baseColor, int overlayColor, float overlayAlpha) {
        return Color.rgb(
                (int) (overlayAlpha * Color.red(baseColor) + (1f - overlayAlpha) * Color.red(overlayColor)),
                (int) (overlayAlpha * Color.green(baseColor) + (1f - overlayAlpha) * Color.green(overlayColor)),
                (int) (overlayAlpha * Color.blue(baseColor) + (1f - overlayAlpha) * Color.blue(overlayColor)));
    }

    /**
     * Computes the lightness value in HSL standard for the given color.
     */
    private static float getLightnessForColor(int color) {
        int red = Color.red(color);
        int green = Color.green(color);
        int blue = Color.blue(color);
        int largest = Math.max(red, Math.max(green, blue));
        int smallest = Math.min(red, Math.min(green, blue));
        int average = (largest + smallest) / 2;
        return average / 255.0f;
    }
}