pinafore/src/routes/_components/compose/ComposeInput.html

<textarea
  id="the-compose-box-input-{realm}"
  class="compose-box-input { size ==='slim' ? 'slim-size' : ''}"
  placeholder="What's on your mind?"
  ref:textarea
  bind:value=rawText
  on:blur="onBlur()"
  on:focus="onFocus()"
  on:selectionChange="onSelectionChange(event)"
  on:keydown="onKeydown(event)"
></textarea>
<label for="the-compose-box-input-{realm}" class="sr-only">
  What's on your mind?
</label>
<style>
  .compose-box-input {
    grid-area: input;
    margin: 10px 0 0 5px;
    padding: 10px;
    border: 1px solid var(--input-border);
    min-height: 75px;
    resize: none;
    overflow: hidden;
    word-wrap: break-word;
    /* Text must be at least 16px or else iOS Safari zooms in */
    font-size: 1.2em;
    /* Hack to make Edge stretch the element all the way to the right.
     * Also desktop Safari makes the gauge stretch too far to the right without it.
     */
    width: calc(100% - 5px);
  }

  .compose-box-input.slim-size {
    max-height: 40vh;
    overflow-y: auto;
  }

  @media (max-width: 767px) {
    .compose-box-input.slim-size {
      max-height: 30vh;
    }
  }

  @media (max-width: 479px) {
    .compose-box-input.slim-size {
      max-height: 20vh;
    }
  }
</style>
<script>
  import { store } from '../../_store/store'
  import { autosize } from '../../_thirdparty/autosize/autosize'
  import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
  import debounce from 'lodash-es/debounce'
  import { mark, stop } from '../../_utils/marks'
  import { selectionChange } from '../../_utils/events'
  import {
    clickSelectedAutosuggestionUsername,
    clickSelectedAutosuggestionEmoji
  } from '../../_actions/autosuggest'
  import { observe } from 'svelte-extras'

  export default {
    oncreate () {
      this.setupSyncFromStore()
      this.setupSyncToStore()
      this.setupAutosize()
    },
    ondestroy () {
      this.teardownAutosize()
    },
    methods: {
      observe,
      setupSyncFromStore () {
        let textarea = this.refs.textarea
        let firstTime = true
        this.observe('text', text => {
          let { rawText } = this.get()
          if (rawText !== text) {
            this.set({ rawText: text })
            // this next autosize is required to resize after
            // the user clicks the "toot" button
            mark('autosize.update()')
            autosize.update(textarea)
            stop('autosize.update()')
          }
          if (firstTime) {
            firstTime = false
            let { autoFocus } = this.get()
            if (autoFocus) {
              requestAnimationFrame(() => textarea.focus())
            }
          }
        })
      },
      setupSyncToStore () {
        const saveStore = debounce(() => scheduleIdleTask(() => this.store.save()), 1000)

        this.observe('rawText', rawText => {
          mark('observe rawText')
          let { realm } = this.get()
          this.store.setComposeData(realm, { text: rawText })
          saveStore()
          stop('observe rawText')
        }, { init: false })
      },
      setupAutosize () {
        let textarea = this.refs.textarea
        requestAnimationFrame(() => {
          mark('autosize()')
          autosize(textarea)
          stop('autosize()')
        })
      },
      teardownAutosize () {
        mark('autosize.destroy()')
        autosize.destroy(this.refs.textarea)
        stop('autosize.destroy()')
      },
      onBlur () {
        scheduleIdleTask(() => {
          this.store.setForCurrentAutosuggest({ composeFocused: false })
        })
      },
      onFocus () {
        scheduleIdleTask(() => {
          let { realm } = this.get()
          this.store.set({ currentComposeRealm: realm })
          this.store.setForCurrentAutosuggest({ composeFocused: true })
        })
      },
      onSelectionChange (selectionStart) {
        scheduleIdleTask(() => {
          this.store.setForCurrentAutosuggest({ composeSelectionStart: selectionStart })
        })
      },
      onKeydown (e) {
        let { keyCode } = e
        // ctrl or cmd (on macs) was pressed; ctrl-enter means post a toot
        const ctrlPressed = e.getModifierState('Control') || e.getModifierState('Meta')
        switch (keyCode) {
          case 9: // tab
            this.clickSelectedAutosuggestion(e)
            break
          case 13: // enter
            const autosuggestionClicked = this.clickSelectedAutosuggestion(e)
            if (!autosuggestionClicked && ctrlPressed) {
              this.fire('postAction')
            }
            break
          case 38: // up
            this.incrementAutosuggestSelected(-1, e)
            break
          case 40: // down
            this.incrementAutosuggestSelected(1, e)
            break
          case 27: // escape
            this.clearAutosuggestions(e)
            break
          default:
        }
      },
      clickSelectedAutosuggestion (event) {
        let {
          autosuggestShown,
          autosuggestType
        } = this.store.get()
        if (!autosuggestShown) {
          return false
        }
        let { realm } = this.get()
        if (autosuggestType === 'account') {
          /* no await */ clickSelectedAutosuggestionUsername(realm)
        } else { // emoji
          /* no await */ clickSelectedAutosuggestionEmoji(realm)
        }
        event.preventDefault()
        event.stopPropagation()
        return true
      },
      incrementAutosuggestSelected (increment, event) {
        let {
          autosuggestShown,
          autosuggestSelected,
          autosuggestSearchResults
        } = this.store.get()
        if (!autosuggestShown) {
          return
        }
        autosuggestSelected += increment
        if (autosuggestSelected >= 0) {
          autosuggestSelected = autosuggestSelected % autosuggestSearchResults.length
        } else {
          autosuggestSelected = autosuggestSearchResults.length + autosuggestSelected
        }
        this.store.setForCurrentAutosuggest({ autosuggestSelected })
        event.preventDefault()
        event.stopPropagation()
      },
      clearAutosuggestions (event) {
        let { autosuggestShown } = this.store.get()
        if (!autosuggestShown) {
          return
        }
        this.store.setForCurrentAutosuggest({
          autosuggestSearchResults: [],
          autosuggestSelected: 0
        })
        event.preventDefault()
        event.stopPropagation()
      }
    },
    store: () => store,
    data: () => ({
      rawText: ''
    }),
    events: {
      selectionChange
    }
  }
</script>