Avoid processing the same file two times when it's used to load a sequence

E.g. If we drop three files (1.png, 2.png, and 3.png), and we load 1.png
as a sequence, we don't want to ask for the third file.

src/app/commands/cmd_open_file.cpp

@@ -8,6 +8,8 @@
 #include "config.h"
 #endif
 
+#include "app/commands/cmd_open_file.h"
+
 #include "app/app.h"
 #include "app/commands/command.h"
 #include "app/commands/params.h"
@@ -32,20 +34,6 @@
 
 namespace app {
 
-class OpenFileCommand : public Command {
-public:
-  OpenFileCommand();
-  Command* clone() const override { return new OpenFileCommand(*this); }
-
-protected:
-  void onLoadParams(const Params& params) override;
-  void onExecute(Context* context) override;
-
-private:
-  std::string m_filename;
-  std::string m_folder;
-};
-
 class OpenFileJob : public Job, public IFileOpProgress
 {
 public:
@@ -104,6 +92,8 @@ void OpenFileCommand::onExecute(Context* context)
 {
   Console console;
 
+  m_usedFiles.clear();
+
   // interactive
   if (context->isUIAvailable() && m_filename.empty()) {
     std::string exts = get_readable_extensions();
@@ -129,6 +119,11 @@ void OpenFileCommand::onExecute(Context* context)
         unrecent = true;
       }
       else {
+        if (fop->isSequence())
+          m_usedFiles = fop->filenames();
+        else
+          m_usedFiles.push_back(fop->filename());
+
         OpenFileJob task(fop);
         task.showProgressWindow();
 

src/app/file/file.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2001-2015  David Capello
+// Copyright (C) 2001-2016  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -69,6 +69,7 @@ namespace app {
     bool isOneFrame() const { return m_oneframe; }
 
     const std::string& filename() const { return m_filename; }
+    const std::vector<std::string>& filenames() const { return m_seq.filename_list; }
     Context* context() const { return m_context; }
     Document* document() const { return m_document; }
     Document* releaseDocument() {

src/app/modules/gui.cpp

@@ -9,6 +9,7 @@
 #endif
 
 #include "app/app.h"
+#include "app/commands/cmd_open_file.h"
 #include "app/commands/command.h"
 #include "app/commands/commands.h"
 #include "app/commands/params.h"
@@ -345,16 +346,13 @@ bool CustomizedGuiManager::onProcessMessage(Message* msg)
 
     case kDropFilesMessage:
       {
-        const DropFilesMessage::Files& files = static_cast<DropFilesMessage*>(msg)->files();
-
-        // Open all files
-        Command* cmd_open_file =
-          CommandsModule::instance()->getCommandByName(CommandId::OpenFile);
-        Params params;
-
+        DropFilesMessage::Files files = static_cast<DropFilesMessage*>(msg)->files();
         UIContext* ctx = UIContext::instance();
 
-        for (const auto& fn : files) {
+        while (!files.empty()) {
+          auto fn = files.front();
+          files.erase(files.begin());
+
           // If the document is already open, select it.
           Document* doc = static_cast<Document*>(ctx->documents().getByFileName(fn));
           if (doc) {
@@ -367,8 +365,17 @@ bool CustomizedGuiManager::onProcessMessage(Message* msg)
           }
           // Load the file
           else {
+            OpenFileCommand cmd;
+            Params params;
             params.set("filename", fn.c_str());
-            ctx->executeCommand(cmd_open_file, params);
+            ctx->executeCommand(&cmd, params);
+
+            // Remove all used file names from the "dropped files"
+            for (const auto& usedFn : cmd.usedFiles()) {
+              auto it = std::find(files.begin(), files.end(), usedFn);
+              if (it != files.end())
+                files.erase(it);
+            }
           }
         }
       }