import QtQuick 2.9
import QtQuick.Templates 2.2 as T
import QtQuick.Controls 2.2
import QtQuick.Controls.impl 2.2
import QtQuick.Controls.Material 2.2
import QtQuick.Controls.Material.impl 2.2

T.Button {
    id: control

    implicitWidth: Math.max(background ? background.implicitWidth : 0,
                            contentItem.implicitWidth + leftPadding + rightPadding)
    implicitHeight: Math.max(background ? background.implicitHeight : 0,
                             contentItem.implicitHeight + topPadding + bottomPadding)
    baselineOffset: contentItem.y + contentItem.baselineOffset

    // external vertical padding is 6 (to increase touch area)
    padding: 12
    leftPadding: padding - 4
    rightPadding: padding - 4

    Material.elevation: flat ? control.down || control.hovered ? 2 : 0
                             : control.down ? 8 : 2
    Material.background: flat ? "transparent" : undefined

    contentItem: Text {
        text: control.text
        font: control.font
        color: app.primaryColor
        horizontalAlignment: Text.AlignHCenter
        verticalAlignment: Text.AlignVCenter
        elide: Text.ElideRight
    }

    // TODO: Add a proper ripple/ink effect for mouse/touch input and focus state
    background: Rectangle {
        implicitWidth: 64
        implicitHeight: 40

        // external vertical padding is 6 (to increase touch area)
        y: 6
        width: parent.width
        height: parent.height - 12
        radius: height / 2
        color: !control.enabled ? control.Material.buttonDisabledColor :
                control.highlighted ? control.Material.highlightedButtonColor : control.Material.accentColor

        PaddedRectangle {
            y: parent.height - 4
            width: parent.width
            height: 4
            radius: 2
            topPadding: -2
            clip: true
            visible: control.checkable && (!control.highlighted || control.flat)
            color: control.checked && control.enabled ? control.Material.accentColor : control.Material.secondaryTextColor
        }

        // The layer is disabled when the button color is transparent so you can do
        // Material.background: "transparent" and get a proper flat button without needing
        // to set Material.elevation as well
        layer.enabled: control.enabled && control.Material.buttonColor.a > 0
        layer.effect: ElevationEffect {
            elevation: control.Material.elevation
        }

        Ripple {
            clipRadius: 2
            width: parent.width
            height: parent.height
            pressed: control.pressed
            anchor: control
            active: control.down || control.visualFocus || control.hovered
            color: control.Material.rippleColor
        }
    }
}
