/
listener.go
61 lines (54 loc) · 1.71 KB
/
listener.go
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//
// Copyright 2021 Bryan T. Meyers <root@datadrake.com>
//
// 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
//
// http://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 input
import (
"github.com/hajimehoshi/ebiten/v2"
)
// KeyListener is a function to call in response to a KeyEvent
type KeyListener func(ke KeyEvent)
var keyListeners map[KeyEvent][]KeyListener
func init() {
keyListeners = make(map[KeyEvent][]KeyListener)
}
// Register associates a KeyListener with a specific KeyEvent
func Register(event KeyEvent, listener KeyListener) {
keyListeners[event] = append(keyListeners[event], listener)
}
// Update reads all of the currently pressed keys and compares them against previously pressed keys to generate KeyEvents
func Update() {
curr := make(keyState)
var mod Modifier
// Get the status of the keys that currently pressed
if ebiten.IsKeyPressed(ebiten.KeyAlt) {
mod |= Alt
}
if ebiten.IsKeyPressed(ebiten.KeyControl) {
mod |= Ctrl
}
for event := range keyListeners {
if ebiten.IsKeyPressed(event.Key) {
curr[event.Key] = true
}
}
// Generate KeyEvents for changes in state
for _, event := range genEvents(last, curr, mod) {
for _, listener := range keyListeners[event] {
listener(event)
}
}
// Update state for next frame
last = curr
}