feat(color): delay load images in SD browser, show 'Loading...' msg (#5376)

radio/src/gui/colorlcd/libui/bitmapbuffer_fileio.cpp

@@ -110,7 +110,7 @@ BitmapBuffer *BitmapBuffer::loadBitmap(const char *filename, BitmapFormats fmt)
   f_close(&imgFile);
 
   if (!img) {
-    TRACE("load_stb(%s) failed: %s", filename, stbi_failure_reason());
+    TRACE("loadBitmap(%s) failed: %s", filename, stbi_failure_reason());
     return nullptr;
   }
 
@@ -122,7 +122,7 @@ BitmapBuffer *BitmapBuffer::loadBitmap(const char *filename, BitmapFormats fmt)
 
   BitmapBuffer *bmp = new BitmapBuffer(dst_fmt, w, h);
   if (bmp == nullptr) {
-    TRACE("convert_stn_bitmap: malloc failed");
+    TRACE("loadBitmap: malloc failed");
     return nullptr;
   }
 

radio/src/gui/colorlcd/radio/radio_sdmanager.cpp

@@ -239,20 +239,48 @@ void RadioSdManagerPage::build(Window * window)
   // Adjust file browser width
   browser->adjustWidth();
 
-  preview = new FilePreview(form, rect_t{0, 0, PREVIEW_W, PREVIEW_H});
-  preview->padAll(PAD_SMALL);
-  grid.add(preview);
+  auto box = new Window(form, {0, 0, PREVIEW_W, PREVIEW_H});
+  grid.add(box);
   grid.nextCell();
 
+  loading = new StaticText(box, {0, 0, LV_SIZE_CONTENT, LV_SIZE_CONTENT}, STR_LOADING);
+  loading->hide();
+  lv_obj_center(loading->getLvObj());
+
+  preview = new FilePreview(box, {0, 0, PREVIEW_W, PREVIEW_H});
+  preview->padAll(PAD_SMALL);
+
   browser->setFileAction([=](const char* path, const char* name, const char* fullpath) {
       fileAction(path, name, fullpath);
   });
   browser->setFileSelected([=](const char* path, const char* name, const char* fullpath) {
-      preview->setFile(fullpath);
+      preview->setFile(nullptr);
+      loading->hide();
+      auto ext = getFileExtension(fullpath);
+      if (strcasecmp(ext, ".bmp") == 0 || strcasecmp(ext, ".png") == 0 ||
+          strcasecmp(ext, ".jpg") == 0 || strcasecmp(ext, ".jpeg") == 0) {
+        previewFilename = fullpath;
+        loadPreview = 10;
+        loading->show();
+      }
   });
   browser->refresh();
 }
 
+void RadioSdManagerPage::checkEvents()
+{
+  PageTab::checkEvents();
+
+  if (loadPreview) {
+    loadPreview -= 1;
+    if (loadPreview == 0) {
+      loading->hide();
+      auto filename = previewFilename;
+      previewFilename = nullptr;
+      preview->setFile(filename);
+    }
+  }
+}
 void RadioSdManagerPage::fileAction(const char* path, const char* name,
                                     const char* fullpath)
 {

radio/src/gui/colorlcd/radio/radio_sdmanager.h

@@ -42,6 +42,10 @@ class RadioSdManagerPage : public PageTab
   static LAYOUT_VAL(PREVIEW_H, LCD_H - 68, (LCD_H - 68) / 3)
 
  protected:
+  int loadPreview = 0;
+  Window* loading = nullptr;
+  const char* previewFilename = nullptr;
+
   void fileAction(const char* path, const char* name, const char* fullpath);
   
   void BootloaderUpdate(const char* fn);
@@ -51,4 +55,6 @@ class RadioSdManagerPage : public PageTab
   void FrSkyFirmwareUpdate(const char* fn, ModuleIndex module);
   void MultiFirmwareUpdate(const char* fn, ModuleIndex module,
                            MultiModuleType type);
+
+  void checkEvents() override; 
 };