/*
 * Copyright 2017 Google Inc.
 *
 * 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
 *
 *     https://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.
 */

package traceviewer.ui

import java.awt.event.ActionListener
import javax.swing.Timer

class RenderState(minX: Double, maxX: Double, viewWidth: Int) {
    var scale: Double
        private set
    var panX: Double
        private set

    val listeners = mutableListOf<() -> Unit>()

    init {
        panX = minX
        scale = viewWidth / (maxX - minX)
    }

    private fun notifyListeners() {
        listeners.forEach { it() }
    }

    fun xViewToWorld(x: Int) = (x / scale) + panX

    fun zoomBy(amount: Double, viewX: Int) {
        val worldX = xViewToWorld(viewX)
        val endScale = scale * amount
        animate(scale, endScale) {
            scale = it
            panX = worldX - (viewX / scale)
            notifyListeners()
        }
    }

    fun pan(deltaX: Int) {
        val endPanX = panX + (deltaX / scale)
        animate(panX, endPanX) { value ->
            panX = value
            notifyListeners()
        }
    }
}