fix: paintWhenInitiallyHidden on Windows/Linux

docs/api/dialog.md

@@ -21,10 +21,7 @@ The `dialog` module has the following methods:
 * `window` [BaseWindow](base-window.md) (optional)
 * `options` Object
   * `title` string (optional)
-  * `defaultPath` string (optional) - Absolute directory path, absolute file
-    path, or file name to use by default. If not provided, the dialog will
-    default to the user's Downloads folder, or their home directory if Downloads
-    doesn't exist.
+  * `defaultPath` string (optional)
   * `buttonLabel` string (optional) - Custom label for the confirmation button, when
     left empty the default label will be used.
   * `filters` [FileFilter[]](structures/file-filter.md) (optional)
@@ -96,10 +93,7 @@ dialog.showOpenDialogSync(mainWindow, {
 * `window` [BaseWindow](base-window.md) (optional)
 * `options` Object
   * `title` string (optional)
-  * `defaultPath` string (optional) - Absolute directory path, absolute file
-    path, or file name to use by default. If not provided, the dialog will
-    default to the user's Downloads folder, or their home directory if Downloads
-    doesn't exist.
+  * `defaultPath` string (optional)
   * `buttonLabel` string (optional) - Custom label for the confirmation button, when
     left empty the default label will be used.
   * `filters` [FileFilter[]](structures/file-filter.md) (optional)
@@ -181,9 +175,7 @@ dialog.showOpenDialog(mainWindow, {
 * `options` Object
   * `title` string (optional) - The dialog title. Cannot be displayed on some _Linux_ desktop environments.
   * `defaultPath` string (optional) - Absolute directory path, absolute file
-    path, or file name to use by default. If not provided, the dialog will
-    default to the user's Downloads folder, or their home directory if Downloads
-    doesn't exist.
+    path, or file name to use by default.
   * `buttonLabel` string (optional) - Custom label for the confirmation button, when
     left empty the default label will be used.
   * `filters` [FileFilter[]](structures/file-filter.md) (optional)
@@ -214,9 +206,7 @@ The `filters` specifies an array of file types that can be displayed, see
 * `options` Object
   * `title` string (optional) - The dialog title. Cannot be displayed on some _Linux_ desktop environments.
   * `defaultPath` string (optional) - Absolute directory path, absolute file
-    path, or file name to use by default. If not provided, the dialog will
-    default to the user's Downloads folder, or their home directory if Downloads
-    doesn't exist.
+    path, or file name to use by default.
   * `buttonLabel` string (optional) - Custom label for the confirmation button, when
     left empty the default label will be used.
   * `filters` [FileFilter[]](structures/file-filter.md) (optional)

docs/breaking-changes.md

@@ -14,17 +14,6 @@ This document uses the following convention to categorize breaking changes:
 
 ## Planned Breaking API Changes (42.0)
 
-### Behavior Changed: Dialog methods default to Downloads directory
-
-The `defaultPath` option for the following methods now defaults to the user's Downloads folder (or their home directory if Downloads doesn't exist) when not explicitly provided:
-
-* `dialog.showOpenDialog`
-* `dialog.showOpenDialogSync`
-* `dialog.showSaveDialog`
-* `dialog.showSaveDialogSync`
-
-Previously, these methods used the last-opened directory or an OS-determined default. To preserve the old behavior, explicitly pass `defaultPath` when calling these methods.
-
 ### Behavior Changed: Offscreen rendering will use `1.0` as default device scale factor.
 
 Previously, OSR used the primary display's device scale factor for rendering, which made the output frame size vary across users.

shell/browser/api/electron_api_browser_window.cc

@@ -49,6 +49,7 @@ BrowserWindow::BrowserWindow(gin::Arguments* args,
   // when initially hidden
   bool paint_when_initially_hidden = true;
   options.Get(options::kPaintWhenInitiallyHidden, &paint_when_initially_hidden);
+  paint_when_initially_hidden_ = paint_when_initially_hidden;
   if (!paint_when_initially_hidden) {
     bool show = true;
     options.Get(options::kShow, &show);
@@ -288,6 +289,17 @@ void BrowserWindow::OnWindowHide() {
   BaseWindow::OnWindowHide();
 }
 
+void BrowserWindow::RenderViewReady() {
+  // When paintWhenInitiallyHidden is true and the native window has not been
+  // shown yet, tell the WebContents it is visible so the renderer's compositor
+  // starts producing frames.  Without this the renderer's LayerTreeHost stays
+  // hidden and no CompositorFrames (and therefore no presentation callbacks)
+  // are ever produced, which means PerformanceObserver paint-timing entries
+  // (first-paint / first-contentful-paint) never fire.
+  if (paint_when_initially_hidden_ && !window()->IsVisible())
+    web_contents()->WasShown();
+}
+
 void BrowserWindow::Show() {
   web_contents()->WasShown();
   BaseWindow::Show();

shell/browser/api/electron_api_browser_window.h

@@ -42,6 +42,7 @@ class BrowserWindow : public BaseWindow,
 
   // content::WebContentsObserver:
   void BeforeUnloadDialogCancelled() override;
+  void RenderViewReady() override;
   void WebContentsDestroyed() override;
 
   // ExtendedWebContentsObserver:
@@ -79,6 +80,12 @@ class BrowserWindow : public BaseWindow,
  private:
   // Helpers.
 
+  // When true and the window is created with show: false, the renderer is
+  // told it is visible as soon as it is ready so that PerformanceObserver
+  // paint‐timing entries (first-paint / first-contentful-paint) are
+  // produced even before the native window is shown.
+  bool paint_when_initially_hidden_ = false;
+
   v8::Global<v8::Value> web_contents_;
   v8::Global<v8::Value> web_contents_view_;
   base::WeakPtr<api::WebContents> api_web_contents_;

shell/browser/ui/file_dialog_linux.cc

@@ -13,7 +13,6 @@
 #include "shell/browser/javascript_environment.h"
 #include "shell/browser/native_window_views.h"
 #include "shell/browser/ui/file_dialog.h"
-#include "shell/common/electron_paths.h"
 #include "shell/common/gin_converters/callback_converter.h"
 #include "shell/common/gin_converters/file_path_converter.h"
 #include "shell/common/gin_helper/dictionary.h"
@@ -82,18 +81,14 @@ class FileChooserDialog : public ui::SelectFileDialog::Listener {
     ui::SelectFileDialog::FileTypeInfo file_info =
         GetFilterInfo(settings.filters);
     ApplySettings(settings);
-    base::FilePath default_path = settings.default_path.empty()
-                                      ? electron::GetDefaultPath()
-                                      : settings.default_path;
-
-    dialog_->SelectFile(ui::SelectFileDialog::SELECT_SAVEAS_FILE,
-                        base::UTF8ToUTF16(settings.title), default_path,
-                        &file_info /* file_types */, 0 /* file_type_index */,
-                        base::FilePath::StringType() /* default_extension */,
-                        settings.parent_window
-                            ? settings.parent_window->GetNativeWindow()
-                            : nullptr,
-                        nullptr);
+    dialog_->SelectFile(
+        ui::SelectFileDialog::SELECT_SAVEAS_FILE,
+        base::UTF8ToUTF16(settings.title), settings.default_path,
+        &file_info /* file_types */, 0 /* file_type_index */,
+        base::FilePath::StringType() /* default_extension */,
+        settings.parent_window ? settings.parent_window->GetNativeWindow()
+                               : nullptr,
+        nullptr);
   }
 
   void RunSaveDialog(gin_helper::Promise<gin_helper::Dictionary> promise,
@@ -113,13 +108,9 @@ class FileChooserDialog : public ui::SelectFileDialog::Listener {
     ui::SelectFileDialog::FileTypeInfo file_info =
         GetFilterInfo(settings.filters);
     ApplySettings(settings);
-    base::FilePath default_path = settings.default_path.empty()
-                                      ? electron::GetDefaultPath()
-                                      : settings.default_path;
-
     dialog_->SelectFile(
         GetDialogType(settings.properties), base::UTF8ToUTF16(settings.title),
-        default_path, &file_info, 0 /* file_type_index */,
+        settings.default_path, &file_info, 0 /* file_type_index */,
         base::FilePath::StringType() /* default_extension */,
         settings.parent_window ? settings.parent_window->GetNativeWindow()
                                : nullptr,

shell/browser/ui/file_dialog_mac.mm

@@ -21,7 +21,6 @@
 #include "content/public/browser/browser_thread.h"
 #include "electron/mas.h"
 #include "shell/browser/native_window.h"
-#include "shell/common/electron_paths.h"
 #include "shell/common/gin_converters/file_path_converter.h"
 #include "shell/common/gin_helper/dictionary.h"
 #include "shell/common/gin_helper/promise.h"
@@ -187,18 +186,14 @@ void SetupDialog(NSSavePanel* dialog, const DialogSettings& settings) {
 
   [dialog setShowsTagField:settings.shows_tag_field];
 
-  base::FilePath default_path = settings.default_path.empty()
-                                    ? electron::GetDefaultPath()
-                                    : settings.default_path;
-
   NSString* default_dir = nil;
   NSString* default_filename = nil;
-  if (!default_path.empty()) {
+  if (!settings.default_path.empty()) {
     electron::ScopedAllowBlockingForElectron allow_blocking;
-    if (base::DirectoryExists(default_path)) {
-      default_dir = base::SysUTF8ToNSString(default_path.value());
+    if (base::DirectoryExists(settings.default_path)) {
+      default_dir = base::SysUTF8ToNSString(settings.default_path.value());
     } else {
-      if (default_path.IsAbsolute()) {
+      if (settings.default_path.IsAbsolute()) {
         default_dir =
             base::SysUTF8ToNSString(settings.default_path.DirName().value());
       }

shell/browser/ui/file_dialog_win.cc

@@ -21,7 +21,6 @@
 #include "base/win/registry.h"
 #include "shell/browser/native_window_views.h"
 #include "shell/browser/ui/win/dialog_thread.h"
-#include "shell/common/electron_paths.h"
 #include "shell/common/gin_converters/file_path_converter.h"
 #include "shell/common/gin_helper/dictionary.h"
 #include "shell/common/gin_helper/promise.h"
@@ -107,12 +106,8 @@ static HRESULT ShowFileDialog(IFileDialog* dialog,
 static void ApplySettings(IFileDialog* dialog, const DialogSettings& settings) {
   std::wstring file_part;
 
-  base::FilePath default_path = settings.default_path.empty()
-                                    ? electron::GetDefaultPath()
-                                    : settings.default_path;
-
-  if (!IsDirectory(default_path))
-    file_part = default_path.BaseName().value();
+  if (!IsDirectory(settings.default_path))
+    file_part = settings.default_path.BaseName().value();
 
   dialog->SetFileName(file_part.c_str());
 
@@ -154,8 +149,8 @@ static void ApplySettings(IFileDialog* dialog, const DialogSettings& settings) {
     }
   }
 
-  if (default_path.IsAbsolute()) {
-    SetDefaultFolder(dialog, default_path);
+  if (settings.default_path.IsAbsolute()) {
+    SetDefaultFolder(dialog, settings.default_path);
   }
 }
 

shell/common/electron_paths.cc

@@ -114,18 +114,4 @@ void RegisterPathProvider() {
                                       PATH_END);
 }
 
-base::FilePath GetDefaultPath() {
-  base::FilePath path;
-
-  ScopedAllowBlockingForElectron allow_blocking;
-  if (base::PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS, &path) &&
-      base::DirectoryExists(path))
-    return path;
-
-  if (base::PathService::Get(base::DIR_HOME, &path))
-    return path;
-
-  return base::FilePath();
-}
-
 }  // namespace electron

shell/common/electron_paths.h

@@ -51,10 +51,6 @@ static_assert(PATH_START < PATH_END, "invalid PATH boundaries");
 // Register the path provider with the base::PathService.
 void RegisterPathProvider();
 
-// Returns a default directory for file dialogs when no default path is
-// provided.
-base::FilePath GetDefaultPath();
-
 }  // namespace electron
 
 #endif  // ELECTRON_SHELL_COMMON_ELECTRON_PATHS_H_

spec/api-browser-window-spec.ts

@@ -6721,28 +6721,35 @@ describe('BrowserWindow module', () => {
     w.loadFile(path.join(fixtures, 'pages', 'send-after-node.html'));
   });
 
-  // TODO(codebytere): fix on Windows and Linux too
-  ifdescribe(process.platform === 'darwin')('window.webContents initial paint', () => {
+  describe('window.webContents initial paint', () => {
     afterEach(closeAllWindows);
-    it('paints when a window is initially hidden', async () => {
-      const w = new BrowserWindow({ show: false });
+    it('paints when a window is initially hidden with paintWhenInitiallyHidden', async () => {
+      const w = new BrowserWindow({
+        show: false,
+        paintWhenInitiallyHidden: true
+      });
       await w.loadFile(path.join(fixtures, 'pages', 'a.html'));
 
       const entries = await w.webContents.executeJavaScript(`
         new Promise((resolve) => {
-          const observer = new PerformanceObserver((performance) => {
-            observer.disconnect();
-            resolve(performance.getEntries());
+          const observer = new PerformanceObserver((list) => {
+            const paintEntries = list.getEntries().filter(
+              e => e.name === 'first-paint' || e.name === 'first-contentful-paint'
+            );
+            if (paintEntries.length > 0) {
+              observer.disconnect();
+              resolve(paintEntries.map(e => e.name));
+            }
           });
           observer.observe({ entryTypes: ['paint'] });
-        });
 
-        const header = document.createElement('h1');
-        header.innerText = 'Paint me!!';
-        document.getElementById('div').appendChild(header);
+          const header = document.createElement('h1');
+          header.innerText = 'Paint me!!';
+          document.getElementById('div').appendChild(header);
+        });
       `);
 
-      expect(JSON.stringify(entries)).to.eq('{}');
+      expect(entries).to.be.an('array').that.includes('first-contentful-paint');
     });
   });