chenhaodong / mew-iview

  <template>

      <div
          :class="[prefixCls + '-hue']"
          tabindex="0"
          @click="$el.focus()"
          @keydown.esc="handleEscape"
          @keydown.left="handleLeft"
          @keydown.right="handleRight"
          @keydown.up="handleUp"
          @keydown.down="handleDown"
      >
          <div
              ref="container"
              :class="[prefixCls + '-hue-container']"
              @mousedown="handleMouseDown"
              @touchmove="handleChange"
              @touchstart="handleChange">
              <div
                  :style="{top: 0, left: `${percent}%`}"
                  :class="[prefixCls + '-hue-pointer']">
                  <div :class="[prefixCls + '-hue-picker']"></div>

              </div>
          </div>
      </div>
  </template>

  <script>

  import HASMixin from './hsaMixin';
  import Prefixes from './prefixMixin';
  import {clamp} from './utils';
  
  export default {
      name: 'Hue',
  
      mixins: [HASMixin, Prefixes],
  
      data() {
          const normalStep = 1 / 360 * 25;
          const jumpStep = 20 * normalStep;
  
          return {
              left: -normalStep,
              right: normalStep,
              up: jumpStep,
              down: -jumpStep,
              powerKey: 'shiftKey',
              percent: clamp(this.value.hsl.h * 100 / 360, 0, 100),
          };
      },
  

      watch: {
          value () {
              this.percent = clamp(this.value.hsl.h * 100 / 360, 0, 100);
          }
      },
  

      methods: {
          change(percent) {
              this.percent = clamp(percent, 0, 100);

              const {h, s, l, a} = this.value.hsl;
              const newHue = clamp(percent / 100 * 360, 0, 360);
  
              if (h !== newHue) {
                  this.$emit('change', {h: newHue, s, l, a, source: 'hsl'});

              }
          },

          handleSlide(e, direction) {
              e.preventDefault();
              e.stopPropagation();

              if (e[this.powerKey]) {
                  this.change(direction < 0 ? 0 : 100);
                  return;
              }

              this.change(this.percent + direction);
          },
          handleChange(e) {
              e.preventDefault();
              e.stopPropagation();

              const left = this.getLeft(e);

              if (left < 0) {
                  this.change(0);
                  return;
              }

              const {clientWidth} = this.$refs.container;
  
              if (left > clientWidth) {
                  this.change(100);
                  return;

              }

  
              this.change(left * 100 / clientWidth);
          },
      },
  };
  </script>