Added the Lazarus_Linux_Console\LibraryBrowser demo

demos/Lazarus_Linux_Console/LibraryBrowser/uencapsulatedbrowser.pas

@@ -0,0 +1,163 @@
+unit uencapsulatedbrowser;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  SyncObjs, SysUtils,
+  ucefbrowserthread;
+
+type
+  TEncapsulatedBrowser = class
+    protected
+      FThread       : TCEFBrowserThread;
+      FWidth        : integer;
+      FHeight       : integer;
+      FDelayMs      : integer;
+      FScale        : single;
+      FSnapshotPath : string;
+      FErrorText    : string;
+      FEvent        : TSimpleEvent;
+
+      procedure Thread_OnError(Sender: TObject);
+      procedure Thread_OnSnapshotAvailable(Sender: TObject);
+
+    public
+      constructor Create;
+      destructor  Destroy; override;
+      procedure   AfterConstruction;
+      procedure   LoadURL(const aURL : string);   
+      function    WaitForEvent : boolean;
+      procedure   WriteResult;
+
+      property Width           : integer   read FWidth          write FWidth;
+      property Height          : integer   read FHeight         write FHeight;
+      property SnapshotPath    : string    read FSnapshotPath   write FSnapshotPath;
+      property ErrorText       : string    read FErrorText;
+  end;
+
+procedure InitializeEncapsulatedBrowser;
+procedure FinalizeEncapsulatedBrowser;
+procedure CaptureScreenshot(const aURL: string);
+
+implementation
+
+var
+  EncapsulatedBrowser : TEncapsulatedBrowser = nil;
+
+procedure InitializeEncapsulatedBrowser;
+begin
+  TCEFBrowserThread.CreateGlobalCEFApp;
+end;
+
+procedure FinalizeEncapsulatedBrowser;
+begin
+  if (EncapsulatedBrowser <> nil) then
+    FreeAndNil(EncapsulatedBrowser);
+
+  TCEFBrowserThread.DestroyGlobalCEFApp;
+end;
+
+procedure CaptureScreenshot(const aURL: string);
+begin
+  EncapsulatedBrowser := TEncapsulatedBrowser.Create;
+  EncapsulatedBrowser.LoadURL(aURL);
+
+  if EncapsulatedBrowser.WaitForEvent then
+    EncapsulatedBrowser.WriteResult;
+end;
+
+constructor TEncapsulatedBrowser.Create;
+begin
+  inherited Create;
+
+  FEvent         := nil;
+  FThread        := nil;
+  FWidth         := 1024;
+  FHeight        := 768;
+  FSnapshotPath  := 'snapshot.png';
+  FErrorText     := '';
+end;
+
+destructor TEncapsulatedBrowser.Destroy;
+begin
+  if (FThread <> nil) then
+    begin
+      FThread.TerminateBrowserThread;
+      FThread.WaitFor;
+      FreeAndNil(FThread);
+    end;
+
+  if (FEvent <> nil) then
+     FreeAndNil(FEvent);
+
+  inherited Destroy;
+end;
+
+procedure TEncapsulatedBrowser.AfterConstruction;
+begin
+  inherited AfterConstruction;
+
+  FEvent := TSimpleEvent.Create;
+end;
+
+procedure TEncapsulatedBrowser.LoadURL(const aURL : string);
+begin
+  if (FThread = nil) then
+    begin
+      FThread                     := TCEFBrowserThread.Create(FWidth, FHeight, aURL, FSnapshotPath);
+      FThread.OnError             := @Thread_OnError;
+      FThread.OnSnapshotAvailable := @Thread_OnSnapshotAvailable;
+      FThread.Start;
+    end
+   else
+    FThread.LoadUrl(aURL);
+end;
+
+procedure TEncapsulatedBrowser.Thread_OnError(Sender: TObject);
+begin
+  // This code is executed in the TCEFBrowserThread thread context while the main application thread is waiting for FEvent.
+
+  FErrorText := 'Error';
+
+  if (FThread.ErrorCode <> 0) then
+    FErrorText := FErrorText + ' ' + inttostr(FThread.ErrorCode);
+
+  FErrorText := FErrorText + ' : ' + FThread.ErrorText;
+
+  if (length(FThread.FailedUrl) > 0) then
+    FErrorText := FErrorText + ' - ' + FThread.FailedUrl;
+
+  if assigned(FEvent) then
+    FEvent.SetEvent;
+end;
+
+procedure TEncapsulatedBrowser.Thread_OnSnapshotAvailable(Sender: TObject);
+begin
+  // This code is executed in the TCEFBrowserThread thread context while the main application thread is waiting for FEvent.
+  if assigned(FEvent) then
+    FEvent.SetEvent;
+end;
+
+function TEncapsulatedBrowser.WaitForEvent : boolean;
+begin
+  Result := True;
+
+  // Wait for 1 minute max.
+  if assigned(FEvent) and (FEvent.WaitFor(60000) = wrTimeout) then
+    begin
+      WriteLn('Timeout expired!');
+      Result := False;
+    end;
+end;
+
+procedure TEncapsulatedBrowser.WriteResult;
+begin
+  if (length(FErrorText) > 0) then
+    WriteLn(FErrorText)
+   else
+    WriteLn('Snapshot saved successfully as ' + FSnapshotPath);
+end;
+
+end.