Merge branch 'master' into MHP30

source/Core/Inc/ScrollMessage.hpp

@@ -0,0 +1,53 @@
+#ifndef SCROLL_MESSAGE_HPP_
+#define SCROLL_MESSAGE_HPP_
+
+#include <stdint.h>
+
+/**
+ * A helper class for showing a full-screen scrolling message.
+ */
+class ScrollMessage {
+  uint32_t messageStart = 0;
+  int16_t  lastOffset   = -1;
+
+  /**
+   * Calcualte the width in pixels of the message string, in the large
+   * font and taking into account multi-byte chars.
+   *
+   * @param message The null-terminated message string.
+   */
+  static uint16_t messageWidth(const char *message);
+
+public:
+  ScrollMessage() {}
+
+  /**
+   * Resets this `ScrollMessage` instance to its initial state.
+   */
+  void reset() {
+    messageStart = 0;
+    lastOffset   = -1;
+  }
+
+  /**
+   * Gets whether this `ScrollMessage` instance is in its initial state.
+   */
+  bool isReset() const { return messageStart == 0; }
+
+  /**
+   * Draw and update the scroll message if needed.
+   *
+   * This function does not call `OLED::refresh()`. If this function
+   * returns `true`, the caller shall call `OLED::refresh()` to draw the
+   * modified framebuffer to the OLED screen.
+   *
+   * @param message The null-terminated message string. This must be the
+   * same string as the previous call, unless this `ScrollMessage` instance
+   * is in its initial state or `reset()` has been called.
+   * @param currentTick The current tick as returned by `xTaskGetTickCount()`.
+   * @return Whether the OLED framebuffer has been modified.
+   */
+  bool drawUpdate(const char *message, uint32_t currentTick);
+};
+
+#endif /* SCROLL_MESSAGE_HPP_ */