feat: add basic support for SVG generator.

Add heat map example.

samples/HeatMap/Components/Layout/MainLayout.razor

@@ -0,0 +1,9 @@
+@inherits LayoutComponentBase
+
+@Body
+
+<div id="blazor-error-ui" data-nosnippet>
+    An unhandled error has occurred.
+    <a href="." class="reload">Reload</a>
+    <span class="dismiss">🗙</span>
+</div>

samples/HeatMap/Components/Layout/MainLayout.razor.css

@@ -0,0 +1,20 @@
+#blazor-error-ui {
+    color-scheme: light only;
+    background: lightyellow;
+    bottom: 0;
+    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
+    box-sizing: border-box;
+    display: none;
+    left: 0;
+    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
+    position: fixed;
+    width: 100%;
+    z-index: 1000;
+}
+
+    #blazor-error-ui .dismiss {
+        cursor: pointer;
+        position: absolute;
+        right: 0.75rem;
+        top: 0.5rem;
+    }

samples/HeatMap/Components/Layout/ReconnectModal.razor

@@ -0,0 +1,31 @@
+<script type="module" src="@Assets["Components/Layout/ReconnectModal.razor.js"]"></script>
+
+<dialog id="components-reconnect-modal" data-nosnippet>
+    <div class="components-reconnect-container">
+        <div class="components-rejoining-animation" aria-hidden="true">
+            <div></div>
+            <div></div>
+        </div>
+        <p class="components-reconnect-first-attempt-visible">
+            Rejoining the server...
+        </p>
+        <p class="components-reconnect-repeated-attempt-visible">
+            Rejoin failed... trying again in <span id="components-seconds-to-next-attempt"></span> seconds.
+        </p>
+        <p class="components-reconnect-failed-visible">
+            Failed to rejoin.<br />Please retry or reload the page.
+        </p>
+        <button id="components-reconnect-button" class="components-reconnect-failed-visible">
+            Retry
+        </button>
+        <p class="components-pause-visible">
+            The session has been paused by the server.
+        </p>
+        <button id="components-resume-button" class="components-pause-visible">
+            Resume
+        </button>
+        <p class="components-resume-failed-visible">
+            Failed to resume the session.<br />Please reload the page.
+        </p>
+    </div>
+</dialog>

samples/HeatMap/Components/Layout/ReconnectModal.razor.css

@@ -0,0 +1,157 @@
+.components-reconnect-first-attempt-visible,
+.components-reconnect-repeated-attempt-visible,
+.components-reconnect-failed-visible,
+.components-pause-visible,
+.components-resume-failed-visible,
+.components-rejoining-animation {
+    display: none;
+}
+
+#components-reconnect-modal.components-reconnect-show .components-reconnect-first-attempt-visible,
+#components-reconnect-modal.components-reconnect-show .components-rejoining-animation,
+#components-reconnect-modal.components-reconnect-paused .components-pause-visible,
+#components-reconnect-modal.components-reconnect-resume-failed .components-resume-failed-visible,
+#components-reconnect-modal.components-reconnect-retrying,
+#components-reconnect-modal.components-reconnect-retrying .components-reconnect-repeated-attempt-visible,
+#components-reconnect-modal.components-reconnect-retrying .components-rejoining-animation,
+#components-reconnect-modal.components-reconnect-failed,
+#components-reconnect-modal.components-reconnect-failed .components-reconnect-failed-visible {
+    display: block;
+}
+
+
+#components-reconnect-modal {
+    background-color: white;
+    width: 20rem;
+    margin: 20vh auto;
+    padding: 2rem;
+    border: 0;
+    border-radius: 0.5rem;
+    box-shadow: 0 3px 6px 2px rgba(0, 0, 0, 0.3);
+    opacity: 0;
+    transition: display 0.5s allow-discrete, overlay 0.5s allow-discrete;
+    animation: components-reconnect-modal-fadeOutOpacity 0.5s both;
+    &[open]
+
+{
+    animation: components-reconnect-modal-slideUp 1.5s cubic-bezier(.05, .89, .25, 1.02) 0.3s, components-reconnect-modal-fadeInOpacity 0.5s ease-in-out 0.3s;
+    animation-fill-mode: both;
+}
+
+}
+
+#components-reconnect-modal::backdrop {
+    background-color: rgba(0, 0, 0, 0.4);
+    animation: components-reconnect-modal-fadeInOpacity 0.5s ease-in-out;
+    opacity: 1;
+}
+
+@keyframes components-reconnect-modal-slideUp {
+    0% {
+        transform: translateY(30px) scale(0.95);
+    }
+
+    100% {
+        transform: translateY(0);
+    }
+}
+
+@keyframes components-reconnect-modal-fadeInOpacity {
+    0% {
+        opacity: 0;
+    }
+
+    100% {
+        opacity: 1;
+    }
+}
+
+@keyframes components-reconnect-modal-fadeOutOpacity {
+    0% {
+        opacity: 1;
+    }
+
+    100% {
+        opacity: 0;
+    }
+}
+
+.components-reconnect-container {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 1rem;
+}
+
+#components-reconnect-modal p {
+    margin: 0;
+    text-align: center;
+}
+
+#components-reconnect-modal button {
+    border: 0;
+    background-color: #6b9ed2;
+    color: white;
+    padding: 4px 24px;
+    border-radius: 4px;
+}
+
+    #components-reconnect-modal button:hover {
+        background-color: #3b6ea2;
+    }
+
+    #components-reconnect-modal button:active {
+        background-color: #6b9ed2;
+    }
+
+.components-rejoining-animation {
+    position: relative;
+    width: 80px;
+    height: 80px;
+}
+
+    .components-rejoining-animation div {
+        position: absolute;
+        border: 3px solid #0087ff;
+        opacity: 1;
+        border-radius: 50%;
+        animation: components-rejoining-animation 1.5s cubic-bezier(0, 0.2, 0.8, 1) infinite;
+    }
+
+        .components-rejoining-animation div:nth-child(2) {
+            animation-delay: -0.5s;
+        }
+
+@keyframes components-rejoining-animation {
+    0% {
+        top: 40px;
+        left: 40px;
+        width: 0;
+        height: 0;
+        opacity: 0;
+    }
+
+    4.9% {
+        top: 40px;
+        left: 40px;
+        width: 0;
+        height: 0;
+        opacity: 0;
+    }
+
+    5% {
+        top: 40px;
+        left: 40px;
+        width: 0;
+        height: 0;
+        opacity: 1;
+    }
+
+    100% {
+        top: 0px;
+        left: 0px;
+        width: 80px;
+        height: 80px;
+        opacity: 0;
+    }
+}

samples/HeatMap/Components/Layout/ReconnectModal.razor.js

@@ -0,0 +1,63 @@
+// Set up event handlers
+const reconnectModal = document.getElementById("components-reconnect-modal");
+reconnectModal.addEventListener("components-reconnect-state-changed", handleReconnectStateChanged);
+
+const retryButton = document.getElementById("components-reconnect-button");
+retryButton.addEventListener("click", retry);
+
+const resumeButton = document.getElementById("components-resume-button");
+resumeButton.addEventListener("click", resume);
+
+function handleReconnectStateChanged(event) {
+    if (event.detail.state === "show") {
+        reconnectModal.showModal();
+    } else if (event.detail.state === "hide") {
+        reconnectModal.close();
+    } else if (event.detail.state === "failed") {
+        document.addEventListener("visibilitychange", retryWhenDocumentBecomesVisible);
+    } else if (event.detail.state === "rejected") {
+        location.reload();
+    }
+}
+
+async function retry() {
+    document.removeEventListener("visibilitychange", retryWhenDocumentBecomesVisible);
+
+    try {
+        // Reconnect will asynchronously return:
+        // - true to mean success
+        // - false to mean we reached the server, but it rejected the connection (e.g., unknown circuit ID)
+        // - exception to mean we didn't reach the server (this can be sync or async)
+        const successful = await Blazor.reconnect();
+        if (!successful) {
+            // We have been able to reach the server, but the circuit is no longer available.
+            // We'll reload the page so the user can continue using the app as quickly as possible.
+            const resumeSuccessful = await Blazor.resumeCircuit();
+            if (!resumeSuccessful) {
+                location.reload();
+            } else {
+                reconnectModal.close();
+            }
+        }
+    } catch (err) {
+        // We got an exception, server is currently unavailable
+        document.addEventListener("visibilitychange", retryWhenDocumentBecomesVisible);
+    }
+}
+
+async function resume() {
+    try {
+        const successful = await Blazor.resumeCircuit();
+        if (!successful) {
+            location.reload();
+        }
+    } catch {
+        location.reload();
+    }
+}
+
+async function retryWhenDocumentBecomesVisible() {
+    if (document.visibilityState === "visible") {
+        await retry();
+    }
+}