Docked auto py-terminal (#1284)

docs/changelog.md

@@ -1,5 +1,14 @@
 # Release Notes
 
+2023.XX.X
+=========
+
+Features
+--------
+
+- Added a `docked` field and attribute for the `<py-terminal>` custom element, enabled by default when the terminal is in `auto` mode, and able to dock the terminal at the bottom of the page with auto scroll on new code execution.
+
+
 2023.01.1
 =========
 

docs/reference/plugins/py-terminal.md

@@ -4,7 +4,9 @@ This is one of the core plugins in PyScript, which is active by default. With it
 
 ## Configuration
 
-You can control how `<py-terminal>` behaves by setting the value of the  `terminal` configuration in your `<py-config>`.
+You can control how `<py-terminal>` behaves by setting the value of the `terminal` configuration in your `<py-config>`, together with the `docked` one.
+
+For the **terminal** field, these are the values:
 
 | value | description |
 |-------|-------------|
@@ -12,11 +14,25 @@ You can control how `<py-terminal>` behaves by setting the value of the  `termin
 | `true` | Automatically add a `<py-terminal>` to the page |
 | `"auto"` | This is the default. Automatically add a `<py-terminal auto>`, to the page. The terminal is initially hidden and automatically shown as soon as something writes to `stdout` and/or `stderr` |
 
+For the **docked** field, these are the values:
+
+| value | description |
+|-------|-------------|
+| `false` | Don't dock `<py-terminal>` to the page |
+| `true` | Automatically dock a `<py-terminal>` to the page |
+| `"docked"` | This is the default. Automatically add a `<py-terminal docked>`, to the page. The terminal, once visible, is automatically shown at the bottom of the page, covering the width of such page |
+
+Please note that **docked** mode is currently used as default only when `terminal="auto"`, or *terminal* default, is used.
+
+In all other cases it's up to the user decide if a terminal should be docked or not.
+
+
 ### Examples
 
 ```html
 <py-config>
     terminal = true
+    docked = false
 </py-config>
 
 <py-script>

pyscriptjs/src/plugins/pyterminal.ts

@@ -6,8 +6,25 @@ import { getLogger } from '../logger';
 import { type Stdio } from '../stdio';
 import { InterpreterClient } from '../interpreter_client';
 
+type AppConfigStyle = AppConfig & { terminal?: boolean | 'auto'; docked?: boolean | 'docked' };
+
 const logger = getLogger('py-terminal');
 
+const validate = (config: AppConfigStyle, name: string, default_: string) => {
+    const value = config[name] as undefined | boolean | string;
+    if (value !== undefined && value !== true && value !== false && value !== default_) {
+        const got = JSON.stringify(value);
+        throw new UserError(
+            ErrorCode.BAD_CONFIG,
+            `Invalid value for config.${name}: the only accepted` +
+                `values are true, false and "${default_}", got "${got}".`,
+        );
+    }
+    if (value === undefined) {
+        config[name] = default_;
+    }
+};
+
 export class PyTerminalPlugin extends Plugin {
     app: PyScriptApp;
 
@@ -16,33 +33,24 @@ export class PyTerminalPlugin extends Plugin {
         this.app = app;
     }
 
-    configure(config: AppConfig & { terminal?: boolean | 'auto' }) {
+    configure(config: AppConfigStyle) {
         // validate the terminal config and handle default values
-        const t = config.terminal;
+        validate(config, 'terminal', 'auto');
-        if (t !== undefined && t !== true && t !== false && t !== 'auto') {
+        validate(config, 'docked', 'docked');
-            const got = JSON.stringify(t);
-            throw new UserError(
-                ErrorCode.BAD_CONFIG,
-                'Invalid value for config.terminal: the only accepted' +
-                    `values are true, false and "auto", got "${got}".`,
-            );
-        }
-        if (t === undefined) {
-            config.terminal = 'auto'; // default value
-        }
     }
 
-    beforeLaunch(config: AppConfig & { terminal?: boolean | 'auto' }) {
+    beforeLaunch(config: AppConfigStyle) {
         // if config.terminal is "yes" or "auto", let's add a <py-terminal> to
         // the document, unless it's already present.
-        const t = config.terminal;
+        const { terminal: t, docked: d } = config;
-        if (t === true || t === 'auto') {
+        const auto = t === true || t === 'auto';
-            if (document.querySelector('py-terminal') === null) {
+        const docked = d === true || d === 'docked';
-                logger.info('No <py-terminal> found, adding one');
+        if (auto && document.querySelector('py-terminal') === null) {
-                const termElem = document.createElement('py-terminal');
+            logger.info('No <py-terminal> found, adding one');
-                if (t === 'auto') termElem.setAttribute('auto', '');
+            const termElem = document.createElement('py-terminal');
-                document.body.appendChild(termElem);
+            if (auto) termElem.setAttribute('auto', '');
-            }
+            if (docked) termElem.setAttribute('docked', '');
+            document.body.appendChild(termElem);
         }
     }
 
@@ -93,6 +101,10 @@ function make_PyTerminal(app: PyScriptApp) {
                 this.autoShowOnNextLine = false;
             }
 
+            if (this.isDocked()) {
+                this.classList.add('py-terminal-docked');
+            }
+
             logger.info('Registering stdio listener');
             app.registerStdioListener(this);
         }
@@ -101,9 +113,16 @@ function make_PyTerminal(app: PyScriptApp) {
             return this.hasAttribute('auto');
         }
 
+        isDocked() {
+            return this.hasAttribute('docked');
+        }
+
         // implementation of the Stdio interface
         stdout_writeline(msg: string) {
             this.outElem.innerText += msg + '\n';
+            if (this.isDocked()) {
+                this.scrollTop = this.scrollHeight;
+            }
             if (this.autoShowOnNextLine) {
                 this.classList.remove('py-terminal-hidden');
                 this.autoShowOnNextLine = false;

pyscriptjs/src/styles/pyscript_base.css

@@ -330,3 +330,20 @@ textarea {
 .py-terminal-hidden {
     display: none;
 }
+
+/* avoid changing the page layout when the terminal is docked and hidden */
+html:has(py-terminal[docked]:not(py-terminal[docked].py-terminal-hidden)) {
+    padding-bottom: 40vh;
+}
+
+py-terminal[docked] {
+    position: fixed;
+    bottom: 0;
+    width: 100vw;
+    max-height: 40vh;
+    overflow: auto;
+}
+
+py-terminal[docked] .py-terminal {
+    margin: 0;
+}

pyscriptjs/tests/integration/test_py_terminal.py

@@ -131,3 +131,18 @@ class TestPyTerminal(PyScriptTest):
         )
         term = self.page.locator("py-terminal")
         assert term.count() == 0
+
+    def test_config_docked(self):
+        """
+        config.docked == "docked" is also the default: a <py-terminal auto docked> is
+        automatically added to the page
+        """
+        self.pyscript_run(
+            """
+            <button id="my-button" py-onClick="print('hello world')">Click me</button>
+            """
+        )
+        term = self.page.locator("py-terminal")
+        self.page.locator("button").click()
+        expect(term).to_be_visible()
+        assert term.get_attribute("docked") == ""