Twidere-App-Android-Twitter.../twidere/src/main/kotlin/org/mariotaku/twidere/view/transformer/AccountsSelectorTransformer.kt

42 lines
1.4 KiB
Kotlin

/*
* Twidere - Twitter client for Android
*
* Copyright (C) 2012-2017 Mariotaku Lee <mariotaku.lee@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.mariotaku.twidere.view.transformer
import androidx.viewpager.widget.ViewPager
import android.view.View
object AccountsSelectorTransformer : ViewPager.PageTransformer {
internal const val selectorAccountsCount: Int = 3
override fun transformPage(page: View, position: Float) {
when {
position < 0 -> {
page.alpha = 1 + position * selectorAccountsCount
}
position > (selectorAccountsCount - 1f) / selectorAccountsCount -> {
page.alpha = (1 - position) * selectorAccountsCount
}
else -> {
page.alpha = 1f
}
}
}
}