Add dynamic pages with clock, date, Home Assistant values and fonts

The hardcoded clock is now the built-in dynamic page "Clock". A dynamic page
has a background bitmap per time of day and up to 8 elements (clock, date,
Home Assistant value, text), each with position, alignment, font and overlay.
Pages are drawn on the ESP32, also for the web previews.

- Pages tab in the web UI: page editor with drag and drop, font upload
  (TTF/OTF converted in the browser to the FDF1 dot font format)
- Built-in fonts Small, Normal, Large and Full height (generated by
  tools/make_builtin_fonts.py), built-in bitmaps Pikachu and Pikachu yawning
- Home Assistant values over the REST API (URL and token in the HA tab)
- Settings version 4: evening settings removed (now time slots of the Clock
  page), old records are converted
- HA Mode dropdown lists the dynamic pages and bitmaps

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/esp32/app.cpp

@@ -1,36 +1,54 @@
 #include "app.h"
 
 #include <string.h>
+#include <time.h>
 
 #include "config.h"
 #include "display/bitmap_store.h"
+#include "display/font_store.h"
+#include "display/page_resources.h"
+#include "display/page_store.h"
+#include "net/ha_api.h"
 #include "system/settings_store.h"
 
 NanoLink nano(Serial2, NANO_RX_PIN, NANO_TX_PIN, RELAY_PIN, NANO_RESET_PIN);
 BROSE9323 display(DISPLAY_WIDTH, DISPLAY_HEIGHT, PANEL_WIDTH);
-FlipdotFrames frames(display);
+FlipdotFrames frames(display, pageResources);
 StatusScreen status(display, nano);
 DisplayController controller(nano, frames);
 
 static Settings settings;
 static bool restart_pending = false;
 static uint32_t restart_at = 0;
+// Not on the stack: about 1.7 KB
+static DynamicPage loaded_page;
 
-// Load the page bitmap into the frames; falls back to the clock when it is gone
+static void showDynamicPage()
+{
+	frames.setDynamicPage(loaded_page);
+	haApiWatch(&loaded_page);
+	controller.setPage(Page::Dynamic);
+}
+
+// Load the page into the frames: a dynamic page or a bitmap; the Clock page when it is gone
 static void applyPage()
 {
-	if (strcmp(settings.page, PAGE_CLOCK) != 0)
+	if (loadPage(settings.page, loaded_page))
 	{
-		uint8_t bitmap[BITMAP_BYTES];
-		if (loadBitmap(settings.page, bitmap))
-		{
-			frames.setPageBitmap(bitmap);
-			controller.setPage(Page::Bitmap);
-			return;
-		}
-		Serial.printf("Page bitmap \"%s\" not found, showing the clock\n", settings.page);
+		showDynamicPage();
+		return;
 	}
-	controller.setPage(Page::Clock);
+	uint8_t bitmap[BITMAP_BYTES];
+	if (loadBitmap(settings.page, bitmap))
+	{
+		frames.setPageBitmap(bitmap);
+		haApiWatch(nullptr);
+		controller.setPage(Page::Bitmap);
+		return;
+	}
+	Serial.printf("Page \"%s\" not found, showing the clock\n", settings.page);
+	builtinPage(DEFAULT_PAGE, loaded_page);
+	showDynamicPage();
 }
 
 // Load the off bitmap into the frames; blank when it is gone
@@ -52,10 +70,18 @@ static void apply()
 	controller.setSettings(settings.schedule, settings.clock);
 	controller.setEffectTime(effectTime(settings.drive));
 	status.setDrive(settings.flip_time, settings.drive);
+	haApiSetSettings(settings.home_assistant);
 	applyOffPage();
 	applyPage();
 }
 
+// Something the current page may use changed: load it again and redraw
+static void reloadPage()
+{
+	applyPage();
+	controller.pageChanged();
+}
+
 const Settings &appSettings()
 {
 	return settings;
@@ -67,7 +93,7 @@ void appLoadSettings()
 	apply();
 }
 
-static bool sameHomeAssistant(const HomeAssistantSettings &a, const HomeAssistantSettings &b)
+static bool sameMqtt(const HomeAssistantSettings &a, const HomeAssistantSettings &b)
 {
 	return a.enabled == b.enabled && a.port == b.port && strcmp(a.host, b.host) == 0 &&
 		   strcmp(a.user, b.user) == 0 && strcmp(a.password, b.password) == 0;
@@ -78,12 +104,12 @@ const char *appSaveSettings(const Settings &new_settings, bool &restart_needed)
 	const char *error = validateSettings(new_settings);
 	if (error)
 		return error;
-	if (strcmp(new_settings.page, PAGE_CLOCK) != 0 && !bitmapExists(new_settings.page))
-		return "Bitmap not found";
+	if (!pageExists(new_settings.page) && !bitmapExists(new_settings.page))
+		return "Page not found";
 	if (new_settings.off_page[0] && !bitmapExists(new_settings.off_page))
 		return "Off bitmap not found";
 
-	restart_needed = !sameHomeAssistant(settings.home_assistant, new_settings.home_assistant);
+	restart_needed = !sameMqtt(settings.home_assistant, new_settings.home_assistant);
 	const DriveSettings &a = settings.drive, &b = new_settings.drive;
 	bool drive_changed = settings.flip_time != new_settings.flip_time || a.flip_gap != b.flip_gap ||
 						 a.pulses != b.pulses || a.effect != b.effect || a.effect_time != b.effect_time ||
@@ -96,12 +122,17 @@ const char *appSaveSettings(const Settings &new_settings, bool &restart_needed)
 	return nullptr;
 }
 
+static void copyName(char *out, const char *name)
+{
+	strncpy(out, name, PAGE_NAME_SIZE - 1);
+	out[PAGE_NAME_SIZE - 1] = '\0';
+}
+
 const char *appSelectPage(const char *name)
 {
-	if (strcmp(name, PAGE_CLOCK) != 0 && !bitmapExists(name))
-		return "Bitmap not found";
-	strncpy(settings.page, name, sizeof(settings.page) - 1);
-	settings.page[sizeof(settings.page) - 1] = '\0';
+	if (!pageExists(name) && !bitmapExists(name))
+		return "Page not found";
+	copyName(settings.page, name);
 	saveSettings(settings);
 	applyPage();
 	return nullptr;
@@ -111,26 +142,92 @@ const char *appSelectOffPage(const char *name)
 {
 	if (name[0] && !bitmapExists(name))
 		return "Bitmap not found";
-	strncpy(settings.off_page, name, sizeof(settings.off_page) - 1);
-	settings.off_page[sizeof(settings.off_page) - 1] = '\0';
+	copyName(settings.off_page, name);
 	saveSettings(settings);
 	applyOffPage();
 	controller.pageChanged();
 	return nullptr;
 }
 
-void appBitmapChanged(const char *name)
+const char *appSaveBitmap(const char *name, const uint8_t *bitmap)
 {
-	if (strcmp(settings.off_page, name) == 0)
-	{
+	if (pageExists(name))
+		return "A page has this name";
+	const char *error = saveBitmap(name, bitmap);
+	if (error)
+		return error;
+	if (sameName(settings.off_page, name))
 		applyOffPage();
-		controller.pageChanged();
-	}
-	if (strcmp(settings.page, name) == 0)
-	{
-		applyPage();
-		controller.pageChanged();
-	}
+	reloadPage(); // the page or its background
+	return nullptr;
+}
+
+// "Used by page X ..." (the returned text stays valid until the next call)
+static const char *usedBy(const String &page)
+{
+	static char message[80];
+	snprintf(message, sizeof(message), "Used by page \"%s\": change that page first", page.c_str());
+	return message;
+}
+
+const char *appDeleteBitmap(const char *name)
+{
+	String user = pageUsingBitmap(name);
+	if (user.length())
+		return usedBy(user);
+	const char *error = deleteBitmap(name);
+	if (error)
+		return error;
+	if (sameName(settings.page, name))
+		appSelectPage(DEFAULT_PAGE);
+	if (sameName(settings.off_page, name))
+		appSelectOffPage(OFF_PAGE_BLANK);
+	return nullptr;
+}
+
+const char *appSavePage(const char *name, const DynamicPage &page)
+{
+	if (bitmapExists(name))
+		return "A bitmap has this name";
+	for (int i = 0; i < page.slot_count; i++)
+		if (page.slots[i].bitmap[0] && !bitmapExists(page.slots[i].bitmap))
+			return "Background bitmap not found";
+	for (int i = 0; i < page.element_count; i++)
+		if (!fontExists(page.elements[i].font))
+			return "Font not found";
+	const char *error = savePage(name, page);
+	if (error)
+		return error;
+	if (sameName(settings.page, name))
+		reloadPage();
+	return nullptr;
+}
+
+const char *appDeletePage(const char *name)
+{
+	const char *error = deletePage(name);
+	if (error)
+		return error;
+	if (sameName(settings.page, name))
+		appSelectPage(DEFAULT_PAGE);
+	return nullptr;
+}
+
+const char *appSaveFont(const char *name, const uint8_t *data, size_t size)
+{
+	const char *error = saveFont(name, data, size);
+	if (error)
+		return error;
+	controller.pageChanged(); // the page may use it
+	return nullptr;
+}
+
+const char *appDeleteFont(const char *name)
+{
+	String user = pageUsingFont(name);
+	if (user.length())
+		return usedBy(user);
+	return deleteFont(name);
 }
 
 void appShowLive(const uint8_t *bitmap)
@@ -144,6 +241,20 @@ void appStopLive()
 	controller.stopLive();
 }
 
+bool appLocalTime(LocalTime &time)
+{
+	struct tm now = {};
+	if (!getLocalTime(&now, 0))
+		return false;
+	time.year = now.tm_year + 1900;
+	time.month = now.tm_mon + 1;
+	time.day = now.tm_mday;
+	time.weekday = now.tm_wday;
+	time.hour = now.tm_hour;
+	time.minute = now.tm_min;
+	return true;
+}
+
 void appRestartLater(uint32_t delay_ms)
 {
 	restart_pending = true;