Mermix/src/App.svelte

<script lang="ts">
  import { fly } from 'svelte/transition';
  import { store } from './lib/store.svelte';
  import StartScreen from './lib/components/StartScreen.svelte';
  import Sidebar from './lib/components/Sidebar.svelte';
  import Toolbar from './lib/components/Toolbar.svelte';
  import Editor from './lib/components/Editor.svelte';
  import Preview from './lib/components/Preview.svelte';
  import GitPanel from './lib/components/GitPanel.svelte';
  import OptimizePanel from './lib/components/OptimizePanel.svelte';
  import Toasts from './lib/components/Toasts.svelte';

  // Editor/preview split ratio (fraction taken by the editor).
  let ratio = $state(0.42);
  let splitting = $state(false);
  let splitHost = $state<HTMLDivElement>();

  function startSplit(e: MouseEvent) {
    splitting = true;
    e.preventDefault();
  }
  function moveSplit(e: MouseEvent) {
    if (!splitting || !splitHost) return;
    const rect = splitHost.getBoundingClientRect();
    ratio = Math.min(0.8, Math.max(0.2, (e.clientX - rect.left) / rect.width));
  }
  function endSplit() {
    splitting = false;
  }

  function onKey(e: KeyboardEvent) {
    if (store.view !== 'editor') return;
    if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === 's') {
      e.preventDefault();
      void store.save();
    }
    // ⌘/Ctrl+E: jump into viewer mode and toggle the quick-edit drawer.
    if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === 'e') {
      e.preventDefault();
      if (store.layout !== 'preview') store.layout = 'preview';
      store.editDrawer = !store.editDrawer;
    }
    if (e.key === 'Escape' && store.editDrawer) {
      store.editDrawer = false;
    }
  }
</script>

<svelte:window onkeydown={onKey} onmousemove={moveSplit} onmouseup={endSplit} />

{#if store.view === 'start'}
  <StartScreen />
{:else}
  <div class="app">
    <Toolbar />
    <div class="body">
      <Sidebar />
      {#if store.activeId}
        <div class="split" bind:this={splitHost} class:splitting>
          {#if store.layout !== 'preview'}
            <div
              class="pane"
              style={store.layout === 'split' ? `width: ${ratio * 100}%` : 'flex: 1'}
            >
              <Editor />
            </div>
          {/if}
          {#if store.layout === 'split'}
            <!-- svelte-ignore a11y_no_noninteractive_element_interactions -->
            <div
              class="gutter"
              role="separator"
              aria-orientation="vertical"
              tabindex="-1"
              onmousedown={startSplit}
            ></div>
          {/if}
          {#if store.layout !== 'code'}
            <div class="pane preview-pane">
              <Preview />
            </div>
          {/if}

          {#if store.layout === 'preview'}
            {#if store.editDrawer}
              <div class="edit-drawer" transition:fly={{ x: -360, duration: 180 }}>
                <div class="drawer-head">
                  <span class="drawer-title">✎ {store.activeName}</span>
                  <div class="drawer-actions">
                    <button onclick={() => store.save()} disabled={!store.dirty}>Save</button>
                    <button class="ghost icon" title="Close (Esc)" onclick={() => (store.editDrawer = false)}>✕</button>
                  </div>
                </div>
                <div class="drawer-body">
                  <Editor />
                </div>
              </div>
            {:else}
              <button
                class="fab"
                title="Quick edit (⌘E)"
                onclick={() => (store.editDrawer = true)}
              >
                ✎ Edit
                {#if store.dirty}<span class="fab-dot"></span>{/if}
              </button>
            {/if}
          {/if}
        </div>
      {:else}
        <div class="no-diagram">
          <div class="muted">No diagram open.</div>
          <div class="faint">Pick one from the sidebar, or create a new diagram with ＋.</div>
        </div>
      {/if}
      {#if store.showOptimize}
        <OptimizePanel />
      {/if}
      {#if store.showGit}
        <GitPanel />
      {/if}
    </div>
  </div>
{/if}

<Toasts />

<style>
  .app {
    height: 100%;
    display: flex;
    flex-direction: column;
  }
  .body {
    flex: 1;
    display: flex;
    min-height: 0;
  }
  .split {
    flex: 1;
    display: flex;
    min-width: 0;
    position: relative;
  }
  .edit-drawer {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: clamp(360px, 42%, 640px);
    display: flex;
    flex-direction: column;
    background: var(--bg-elev);
    border-right: 1px solid var(--border-strong);
    box-shadow: 8px 0 32px rgba(0, 0, 0, 0.45);
    z-index: 20;
  }
  .drawer-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 8px 8px 14px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
  }
  .drawer-title {
    font-size: 13px;
    font-weight: 600;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .drawer-actions {
    display: flex;
    gap: 6px;
    align-items: center;
  }
  .drawer-body {
    flex: 1;
    min-height: 0;
  }
  .fab {
    position: absolute;
    left: 16px;
    bottom: 16px;
    z-index: 25;
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 9px 16px;
    border-radius: 999px;
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
    box-shadow: 0 6px 22px rgba(124, 92, 255, 0.45);
  }
  .fab:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
  }
  .fab-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--amber);
  }
  .split.splitting {
    cursor: col-resize;
    user-select: none;
  }
  .pane {
    min-width: 0;
    height: 100%;
    overflow: hidden;
  }
  .preview-pane {
    flex: 1;
  }
  .gutter {
    width: 5px;
    flex-shrink: 0;
    background: var(--border);
    cursor: col-resize;
    transition: background 0.12s ease;
  }
  .gutter:hover {
    background: var(--accent);
  }
  .no-diagram {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    text-align: center;
  }
</style>