Initialize subsystems on first TApplication construction

Commit 6ece4c2 restored the original subsystem initialization code. However, this code always ends up calling TScreen::resume. Setting up the display does not work in headless environments or when TERM is not set. Non-graphic applications linking against the library would thus fail to run. Therefore, it's best to initialize them on the first TApplication construction instead of before main().
magiblot · Sep 19, 2023 · 3018453 · 3018453
1 parent a70073c
commit 3018453
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Showing 6 changed files with 28 additions and 17 deletions.
diff --git a/README.md b/README.md
@@ -384,6 +384,7 @@ The following are new features not available in Borland's release of Turbo Visio
     * Many functions which originally had null-terminated string parameters now receive `TStringView` instead. `TStringView` is compatible with `std::string_view`, `std::string` and `const char *` (even `nullptr`).
 * New class `TSpan<T>`, inspired by `std::span`.
 * New classes `TDrawSurface` and `TSurfaceView`, see `<tvision/surface.h>`.
+* The system integration subsystems (`THardwareInfo`, `TScreen`, `TEventQueue`...) are now initialized when constructing a `TApplication` for the first time, rather than before `main`. They are still destroyed on exit from `main`.
 * New method `TVMemMgr::reallocateDiscardable()` which can be used along `allocateDiscardable` and `freeDiscardable`.
 * New method `TView::textEvent()` which allows receiving text in an efficient manner, see [Clipboard interaction](#clipboard).
 * New class `TClipboard`, see [Clipboard interaction](#clipboard).

diff --git a/include/tvision/app.h b/include/tvision/app.h
@@ -310,7 +310,16 @@ class TProgram : public TGroup, public virtual TProgInit
 #if defined( Uses_TApplication ) && !defined( __TApplication )
 #define __TApplication
 
-class TApplication : public TProgram
+class TSubsystemsInit
+{
+
+public:
+
+    TSubsystemsInit() noexcept;
+
+};
+
+class TApplication : public virtual TSubsystemsInit, public TProgram
 {
 
 protected:

diff --git a/include/tvision/system.h b/include/tvision/system.h
@@ -274,7 +274,6 @@ class TEventQueue
 
 private:
 
-    static TMouse _NEAR mouse;
     static Boolean getMouseState( TEvent& ) noexcept;
     static Boolean getPasteEvent( TEvent& ) noexcept;
     static void getKeyOrPasteEvent( TEvent& ) noexcept;

diff --git a/source/tvision/tapplica.cpp b/source/tvision/tapplica.cpp
@@ -17,7 +17,6 @@
 #define Uses_THardwareInfo
 #define Uses_TScreen
 #define Uses_TObject
-#define Uses_TMouse
 #define Uses_TApplication
 #define Uses_TDeskTop
 #include <tvision/tv.h>
@@ -26,15 +25,18 @@
 #include <stdlib.h>
 #include <signal.h>
 
-static THardwareInfo hwInfoManager;
-TMouse _NEAR TEventQueue::mouse;
-static TScreen tsc;
-static TEventQueue teq;
-static TSystemError sysErr;
-
 void initHistory();
 void doneHistory();
 
+TSubsystemsInit::TSubsystemsInit() noexcept
+{
+    static THardwareInfo hwInfoManager;
+    static TMouse tms;
+    static TScreen tsc;
+    static TEventQueue teq;
+    static TSystemError sysErr;
+}
+
 TApplication::TApplication() noexcept :
     TProgInit( &TApplication::initStatusLine,
                   &TApplication::initMenuBar,

diff --git a/source/tvision/tevent.cpp b/source/tvision/tevent.cpp
@@ -74,18 +74,18 @@ TEventQueue::TEventQueue() noexcept
 
 void TEventQueue::resume() noexcept
 {
-    if( mouse.present() == False )
-        mouse.resume();
-    if( mouse.present() == False )
+    if( TMouse::present() == False )
+        TMouse::resume();
+    if( TMouse::present() == False )
         return;
 
-    mouse.getEvent( curMouse );
+    TMouse::getEvent( curMouse );
     lastMouse = curMouse;
 
 #if defined( __FLAT__ )
     THardwareInfo::clearPendingEvent();
 #else
-    mouse.registerHandler( 0xFFFF, (void (_FAR *)()) mouseInt );
+    TMouse::registerHandler( 0xFFFF, (void (_FAR *)()) mouseInt );
 #endif
 
     mouseEvents = True;
@@ -95,7 +95,7 @@ void TEventQueue::resume() noexcept
 
 void TEventQueue::suspend() noexcept
 {
-    mouse.suspend();
+    TMouse::suspend();
 }
 
 TEventQueue::~TEventQueue()

diff --git a/source/tvision/tprogram.cpp b/source/tvision/tprogram.cpp
@@ -316,7 +316,7 @@ void TProgram::setScreenMode( ushort mode )
 {
     TRect  r;
 
-    TEventQueue::mouse.hide(); //HideMouse();
+    TMouse::hide();
     TScreen::setVideoMode( mode );
     initScreen();
     buffer = TScreen::screenBuffer;
@@ -325,7 +325,7 @@ void TProgram::setScreenMode( ushort mode )
     setState(sfExposed, False);
     setState(sfExposed, True);
     redraw();
-    TEventQueue::mouse.show(); //ShowMouse();
+    TMouse::show();
 }
 
 TTimerId TProgram::setTimer( uint timeoutMs, int periodMs )