feat: add image paste support and clipboard documentation

README.md

@@ -112,7 +112,7 @@ Interactive Commands for Text Input:
     Alt-Delete  delete next word
     Alt-Tab     insert tab (four spaces)
     Alt-c       copy input buffer to clipboard (if no message selected)
-    Alt-v       paste into input buffer from clipboard
+    Alt-v       paste text or attach image from clipboard
     Alt-x       cut input buffer to clipboard
 
 
@@ -583,7 +583,9 @@ or a chat.
 ### confirm_send_pasted_image
 
 Specifies whether to prompt the user for confirmation when pasting an image
-to a chat.
+to a chat. Pasted images are attached to the current chat and sent when the
+message is sent; existing input text is used as caption when transfer captions
+are enabled.
 
 ### desktop_notify_active_current
 

doc/CLIPBOARD.md

@@ -1,8 +1,16 @@
 Clipboard
 =========
 On supported platforms (macOS, X11, Wayland) nchat uses the system
-clipboard. For other platforms, or custom behavior, one may configure below
-parameters in `app.conf`.
+clipboard. Text paste inserts clipboard text into the input buffer. Image
+paste attaches the clipboard image to the current chat after optional
+confirmation. The attached image is sent when the message is sent.
+
+For other platforms, or custom behavior, one may configure below parameters in
+`app.conf`.
+
+Image paste requires nchat to be built with `libpng` support. Wayland image
+paste uses `wl-clipboard` by default. X11 and macOS use the bundled clipboard
+backend when no custom image commands are configured.
 
 **Note:** The examples provided below are mainly for reference, not useful
 as actual configuration values (except the `File-based` examples), as the
@@ -44,9 +52,11 @@ Examples:
 ### clipboard_paste_image_command
 
 Specifies a custom image paste command to be used instead of system clipboard.
+The command shall write PNG image bytes to stdout. nchat redirects stdout to a
+temporary `.png` file and verifies that the result is non-empty PNG data before
+sending it.
 Examples:
 
 | Platform    | Command                                                   |
 |-------------|-----------------------------------------------------------|
 | Wayland     | `wl-paste --type image/png`                               |
-

lib/ncutil/src/clipboard.cpp

@@ -14,6 +14,8 @@
 #include <stdexcept>
 #include <vector>
 
+#include <sys/stat.h>
+
 #ifdef HAVE_PNG_H
 #include <png.h>
 #endif
@@ -63,6 +65,31 @@ bool IsDisplayServer(DisplayServer p_DisplayServer)
   return (p_DisplayServer == displayServer);
 }
 
+static std::string ShellQuote(const std::string& p_Str)
+{
+  std::string quoted = "'";
+  for (char c : p_Str)
+  {
+    if (c == '\'')
+    {
+      quoted += "'\\''";
+    }
+    else
+    {
+      quoted += c;
+    }
+  }
+
+  quoted += "'";
+  return quoted;
+}
+
+static bool IsNonEmptyFile(const std::string& p_Path)
+{
+  struct stat sb;
+  return (stat(p_Path.c_str(), &sb) == 0) && S_ISREG(sb.st_mode) && (sb.st_size > 0);
+}
+
 #ifdef HAVE_PNG_H
 static bool WriteRgbaPng(const std::string& p_Path, unsigned p_W, unsigned p_H, const uint8_t* p_Rgba, size_t p_Stride)
 {
@@ -222,7 +249,7 @@ void Clipboard::SetText(const std::string& p_Text)
   {
     const std::string tempPath = FileUtil::GetTempDir() + "/clipboard.txt";
     FileUtil::WriteFile(tempPath, p_Text);
-    const std::string cmd = "cat " + tempPath + " | " + clipboardCopyCommand;
+    const std::string cmd = "cat " + ShellQuote(tempPath) + " | " + clipboardCopyCommand;
     SysUtil::RunCommand(cmd);
     FileUtil::RmFile(tempPath);
   }
@@ -300,9 +327,26 @@ bool Clipboard::GetImage(const std::string& p_Path)
 
   if (!clipboardPasteImageCommand.empty())
   {
-    std::string command = clipboardPasteImageCommand + " | tee " + p_Path;
-    bool rv = SysUtil::RunCommand(command);
-    return rv;
+    const std::string command = clipboardPasteImageCommand + " > " + ShellQuote(p_Path);
+    if (!SysUtil::RunCommand(command))
+    {
+      return false;
+    }
+
+    if (!IsNonEmptyFile(p_Path))
+    {
+      LOG_WARNING("clipboard image output is empty");
+      return false;
+    }
+
+    std::string mimeType = FileUtil::GetMimeType(p_Path);
+    if (!mimeType.empty() && (mimeType != "image/png"))
+    {
+      LOG_WARNING("clipboard image output is not png: %s", mimeType.c_str());
+      return false;
+    }
+
+    return true;
   }
   else
   {

src/main.cpp

@@ -700,7 +700,7 @@ void ShowHelp()
     "    Alt-Backsp  delete previous word\n"
     "    Alt-Delete  delete next word\n"
     "    Alt-c       copy input buffer to clipboard (if no message selected)\n"
-    "    Alt-v       paste into input buffer from clipboard\n"
+    "    Alt-v       paste text or attach image from clipboard\n"
     "    Alt-x       cut input buffer to clipboard\n"
     "\n"
     "Report bugs at https://github.com/d99kris/nchat\n"

src/nchat.1

@@ -190,7 +190,7 @@ Alt\-c
 copy input buffer to clipboard (if no message selected)
 .TP
 Alt\-v
-paste into input buffer from clipboard
+paste text or attach image from clipboard
 .TP
 Alt\-x
 cut input buffer to clipboard

src/uimodel.cpp

@@ -183,6 +183,16 @@ void UiModel::Impl::SendMessage()
   std::string chatId = m_CurrentChat.second;
   std::wstring& entryStr = m_EntryStr[profileId][chatId];
   int& entryPos = m_EntryPos[profileId][chatId];
+  std::vector<std::string>& pendingFilePaths = GetPendingFilePaths(profileId, chatId);
+
+  if (!pendingFilePaths.empty())
+  {
+    std::vector<std::string> filePaths = pendingFilePaths;
+    pendingFilePaths.clear();
+    TransferFile(filePaths);
+    FileUtil::RmFilesByAge(FileUtil::GetTempDir(), "clipboard-*.png", 3600);
+    return;
+  }
 
   if (entryStr.empty()) return;
 
@@ -1390,6 +1400,12 @@ void UiModel::Impl::TransferFile(const std::vector<std::string>& p_FilePaths)
   SetHistoryInteraction(true);
 }
 
+std::vector<std::string>& UiModel::Impl::GetPendingFilePaths(const std::string& p_ProfileId,
+                                                             const std::string& p_ChatId)
+{
+  return m_PendingFilePaths[p_ProfileId][p_ChatId];
+}
+
 void UiModel::Impl::InsertEmoji(const std::wstring& p_Emoji)
 {
   std::string profileId = m_CurrentChat.first;
@@ -5627,6 +5643,12 @@ void UiModel::OnKeyPaste()
 {
   if (Clipboard::HasImage())
   {
+    {
+      std::unique_lock<owned_mutex> lock(m_ModelMutex);
+      if (GetImpl().GetEditMessageActive()) return;
+      GetImpl().AnyUserKeyInput();
+    }
+
     // Open modal dialog without model mutex held
     static const bool confirmSendPastedImage = UiConfig::GetBool("confirm_send_pasted_image");
     if (confirmSendPastedImage)
@@ -5638,23 +5660,31 @@ void UiModel::OnKeyPaste()
     }
 
     static int index = 0;
-    ++index;
-    const std::string tempPath = FileUtil::GetTempDir() + "/clipboard-" + std::to_string(index) + ".png";
+    const std::string tempDir = FileUtil::GetTempDir();
+    std::string tempPath;
+    do
+    {
+      tempPath = tempDir + "/clipboard-" + std::to_string(getpid()) + "-" +
+        std::to_string(TimeUtil::GetCurrentTimeMSec()) + "-" + std::to_string(++index) + ".png";
+    } while (FileUtil::Exists(tempPath));
+
     if (!Clipboard::GetImage(tempPath))
     {
       MessageDialog("Warning", "Failed getting clipboard image.", 0.7, 5);
+      FileUtil::RmFile(tempPath);
       return;
     }
 
-    const std::vector<std::string> tempPaths = { tempPath };
-
     {
       std::unique_lock<owned_mutex> lock(m_ModelMutex);
-      GetImpl().TransferFile(tempPaths);
+      std::pair<std::string, std::string>& currentChat = GetImpl().GetCurrentChat();
+      GetImpl().GetPendingFilePaths(currentChat.first, currentChat.second).push_back(tempPath);
     }
 
-    // Delete temp clipboard images after some time, allowing for it to be sent async
-    FileUtil::RmFilesByAge(FileUtil::GetTempDir(), "clipboard-*.png", 60);
+    MessageDialog("Info", "Image attached. Press send to send it.", 0.6, 5);
+
+    // Delete stale temp clipboard images, keeping recent staged/sending files available.
+    FileUtil::RmFilesByAge(tempDir, "clipboard-*.png", 3600);
   }
   else
   {

src/uimodel.h

@@ -74,6 +74,7 @@ class UiModel
     void OnKeyOpenLink();
     std::string OnKeySaveAttachment(std::string p_FilePath = std::string());
     void TransferFile(const std::vector<std::string>& p_FilePaths);
+    std::vector<std::string>& GetPendingFilePaths(const std::string& p_ProfileId, const std::string& p_ChatId);
     void InsertEmoji(const std::wstring& p_Emoji);
     void InsertText(const std::wstring& p_Text);
     void RequestGroupMembers(const std::string& p_ProfileId, const std::string& p_ChatId);
@@ -271,6 +272,7 @@ class UiModel
 
     std::unordered_map<std::string, std::unordered_map<std::string, std::wstring>> m_EntryStr;
     std::unordered_map<std::string, std::unordered_map<std::string, int>> m_EntryPos;
+    std::unordered_map<std::string, std::unordered_map<std::string, std::vector<std::string>>> m_PendingFilePaths;
 
     std::unordered_map<std::string, std::unordered_map<std::string, std::wstring>> m_EntryStrCleared;
     std::unordered_map<std::string, std::unordered_map<std::string, int>> m_EntryPosCleared;