Bangle.js2: Ensure overlays don't use the current Graphics colors

Author: gfwilliams

ChangeLog

@@ -14,6 +14,7 @@
             E.defrag now defrags with interrupts enabled (also fix potential crash with 2 flat strings end to end)
             Swap to using locks for watch&timer arrays (uses 4b more RAM, but faster and no defrag issues)
             Bangle.js2: Remove buzz when going back in a menu using the button (not the widget)
+            Bangle.js2: Ensure overlays don't use the current Graphics colors
 
      2v28 : Add `E.internal` as a way to access the 'hidden root' containing Espruino internal variables that previously needed `global["\xff"]`
             Bangle.js: Fix back handler not removed when using E.setUI with a back button but without widgets (#2636)

libs/graphics/lcd_memlcd.c

@@ -291,8 +291,18 @@ void lcdMemLCD_flip(JsGraphics *gfx) {
 
   bool hasOverlay = false;
   GfxDrawImageInfo overlayImg;
-  if (lcdOverlayImage)
+  if (lcdOverlayImage) {
+    // Set colors to current theme
+    unsigned int oldFgColor = gfx->data.fgColor;
+    unsigned int oldBgColor = gfx->data.bgColor;
+    gfx->data.fgColor = graphicsTheme.fg;
+    gfx->data.bgColor = graphicsTheme.bg;
+    // parse image (which will generate palette)
     hasOverlay = _jswrap_graphics_parseImage(gfx, lcdOverlayImage, 0, &overlayImg);
+    // Restore colors to previous state
+    gfx->data.fgColor = oldFgColor;
+    gfx->data.bgColor = oldBgColor;
+  }
 
   jshPinSetValue(LCD_SPI_CS, 1);
   if (hasOverlay) {
@@ -311,11 +321,6 @@ void lcdMemLCD_flip(JsGraphics *gfx) {
     bool isRotated180 = (graphicsInternal.data.flags & (JSGRAPHICSFLAGS_SWAP_XY | JSGRAPHICSFLAGS_INVERT_X | JSGRAPHICSFLAGS_INVERT_Y)) ==
                       (JSGRAPHICSFLAGS_INVERT_X | JSGRAPHICSFLAGS_INVERT_Y);
     int ovY = isRotated180 ? (LCD_HEIGHT-(lcdOverlayY+overlayImg.height)) : lcdOverlayY;
-    // Set colors to current theme
-    unsigned int oldFgColor = gfx->data.fgColor;
-    unsigned int oldBgColor = gfx->data.bgColor;
-    gfx->data.fgColor = graphicsTheme.fg;
-    gfx->data.bgColor = graphicsTheme.bg;
     // initialise image layer
     GfxDrawImageLayer l;
     l.x1 = 0;
@@ -359,9 +364,6 @@ void lcdMemLCD_flip(JsGraphics *gfx) {
     jshSPISendMany(LCD_SPI, lcdBuffer, NULL, 2, NULL);
     lcdMemLCD_flip_spi_callback();
 #endif
-    // Restore colors to previous state
-    gfx->data.fgColor = oldFgColor;
-    gfx->data.bgColor = oldBgColor;
   } else { // standard, non-overlay
 #ifdef EMULATED
     memcpy(fakeLCDBuffer, lcdBuffer, LCD_HEIGHT*LCD_STRIDE);