winscp/source/components/ThemePageControl.cpp

//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop

#include <Common.h>
#include <vsstyle.h>
#include <memory>
#include <PasTools.hpp>
#include <TBXOfficeXPTheme.hpp>
#include "ThemePageControl.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
//---------------------------------------------------------------------------
// Based on
// https://www.codeproject.com/Articles/6355/XP-Themes-Tab-Control-in-any-orientation
//---------------------------------------------------------------------------
//#define USE_DEFAULT_XP_TOPTAB     // XP top tab is drawn only for test purpose. To use default, uncoment this line
//---------------------------------------------------------------------------
// constant string definitions here (or you can put it into resource string table)
#define IDS_UTIL_TAB            L"TAB"
#define IDS_UTIL_UXTHEME        L"UxTheme.dll"
#define IDS_UTIL_THEMEACT       "IsThemeActive"
#define IDS_UTIL_THEMEOPN       "OpenThemeData"
#define IDS_UTIL_THEMEBCKG      "DrawThemeBackground"
//---------------------------------------------------------------------------
static inline void ValidCtrCheck(TThemePageControl *)
{
  new TThemePageControl(NULL);
}
//---------------------------------------------------------------------------
namespace Themepagecontrol
{
  void __fastcall PACKAGE Register()
  {
    TComponentClass classes[1] = {__classid(TThemePageControl)};
    RegisterComponents(L"Scp", classes, 0);
  }
}
//----------------------------------------------------------------------------------------------------------
__fastcall TThemeTabSheet::TThemeTabSheet(TComponent * Owner) :
  TTabSheet(Owner)
{
  FShadowed = false;
  FShowCloseButton = false;
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemeTabSheet::Invalidate()
{
  TThemePageControl * ThemePageControl = dynamic_cast<TThemePageControl *>(Parent);
  if (DebugAlwaysTrue(ThemePageControl != NULL))
  {
    ThemePageControl->InvalidateTab(TabIndex);
  }
  else
  {
    Parent->Invalidate();
  }
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemeTabSheet::SetShadowed(bool Value)
{
  if (Shadowed != Value)
  {
    FShadowed = Value;
    Invalidate();
  }
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemeTabSheet::SetShowCloseButton(bool Value)
{
  if (ShowCloseButton != Value)
  {
    FShowCloseButton = Value;
    Invalidate();
  }
}
//----------------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------------
__fastcall TThemePageControl::TThemePageControl(TComponent * Owner) :
  TPageControl(Owner)
{
  FOldTabIndex = -1;
  FHotCloseButton = -1;
}
//----------------------------------------------------------------------------------------------------------
int __fastcall TThemePageControl::GetTabsHeight()
{
  // Calculated height includes tab/contents separator line on Windows 7/8,
  // but not on Windows XP

  TRect Rect = GetClientRect();
  ::SendMessage(Handle, TCM_ADJUSTRECT, FALSE, (LPARAM)&Rect);
  int Result = Rect.Top - 1;

  // Two different ways to calculate the same, not sure which one is more reliable,
  // so we want to know in case they differ.
  if (DebugAlwaysTrue(PageCount >= 0))
  {
    TRect Rect = TabRect(0);
    int Result2 = Rect.Bottom + 1;
    // On Windows 10 with 200% scaling, the first is 40, the second is 42.
    // With 250% scaling its 50 vs 53.
    // Using the larger.
    if (Result2 > Result)
    {
      DebugAssert(IsWin10());
      Result = Result2;
    }
  }

  return Result;
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::PaintWindow(HDC DC)
{
  // Themes not enabled, give up
  if (!UseThemes())
  {
    TPageControl::PaintWindow(DC);
    return;
  }

  // TODO use GetClipBox

  TRect PageRect = GetClientRect();

  // 1st paint the tab body
  TRect ClientRect = PageRect;
  ::SendMessage(Handle, TCM_ADJUSTRECT, FALSE, (LPARAM)&PageRect);

  ClientRect.Top = PageRect.Top - 2;
  DrawThemesXpTabItem(DC, -1, ClientRect, true, 0);

  // 2nd paint the inactive tabs

  int SelectedIndex = TabIndex; // optimization

  for (int Tab = 0; Tab < PageCount; Tab++)
  {
    if (Tab != SelectedIndex)
    {
      DrawThemesXpTab(DC, Tab);
    }
  }

  if (SelectedIndex >= 0)
  {
    DrawThemesXpTab(DC, TabIndex);
  }
}
//----------------------------------------------------------------------------------------------------------
bool __fastcall TThemePageControl::HasTabCloseButton(int Index)
{
  TThemeTabSheet * ThemeTabSheet = dynamic_cast<TThemeTabSheet *>(Pages[Index]);
  return (ThemeTabSheet != NULL) ? ThemeTabSheet->ShowCloseButton : false;
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::DrawThemesXpTab(HDC DC, int Tab)
{
  TThemeTabSheet * ThemeTabSheet = dynamic_cast<TThemeTabSheet *>(Pages[Tab]);
  bool Shadowed = (ThemeTabSheet != NULL) ? ThemeTabSheet->Shadowed : false;
  TRect Rect = TabRect(Tab);
  ItemTabRect(Tab, Rect);
  int State;
  if (Tab != TabIndex)
  {
    TPoint Point = ScreenToClient(Mouse->CursorPos);
    int HotIndex = IndexOfTabAt(Point.X, Point.Y);
    State = (Tab == HotIndex ? TIS_HOT : (Shadowed ? TIS_DISABLED : TIS_NORMAL));
  }
  else
  {
    State = TIS_SELECTED;
  }
  DrawThemesXpTabItem(DC, Tab, Rect, false, State);
}
//----------------------------------------------------------------------------------------------------------
// This function draws Themes Tab control parts: a) Tab-Body and b) Tab-tabs
void __fastcall TThemePageControl::DrawThemesXpTabItem(HDC DC, int Item,
  const TRect & Rect, bool Body, int State)
{
  TSize Size = Rect.Size;

  // Draw background
  HDC DCMem = CreateCompatibleDC(DC);
  HBITMAP BitmapMem = CreateCompatibleBitmap(DC, Size.Width, Size.Height);
  HBITMAP BitmapOld = (HBITMAP)SelectObject(DCMem, BitmapMem);

  TRect RectMem(0, 0, Size.Width, Size.Height);
  TRect RectItemMem(RectMem);
  if (!Body && (State == TIS_SELECTED))
  {
    RectMem.Bottom++;
  }

  if (Body)
  {
    DrawThemesPart(DCMem, TABP_PANE, State, IDS_UTIL_TAB, &RectMem);
  }
  else
  {
    DrawThemesPart(DCMem, TABP_TABITEM, State, IDS_UTIL_TAB, &RectMem);
  }

  // Init some extra parameters
  BITMAPINFO BitmapInfo;
  // Fill local pixel arrays
  ZeroMemory(&BitmapInfo, sizeof(BITMAPINFO));
  BITMAPINFOHEADER & BitmapInfoHeader = BitmapInfo.bmiHeader;
  BitmapInfoHeader.biSize = sizeof(BITMAPINFOHEADER);
  BitmapInfoHeader.biCompression = BI_RGB;
  BitmapInfoHeader.biPlanes = 1;
  // force as RGB: 3 bytes,24 bits -> good for rotating bitmap in any resolution
  BitmapInfoHeader.biBitCount = 24;
  BitmapInfoHeader.biWidth = Size.Width;
  BitmapInfoHeader.biHeight = Size.Height;

  if (!Body && (Item >= 0))
  {
    DrawTabItem(DCMem, Item, Rect, RectItemMem, (State == TIS_SELECTED), (State == TIS_DISABLED));
  }

  // Blit image to the screen
  BitBlt(DC, Rect.Left, Rect.Top, Size.Width, Size.Height, DCMem, 0, 0, SRCCOPY);
  SelectObject(DCMem, BitmapOld);
  DeleteObject(BitmapMem);
  DeleteDC(DCMem);
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::ItemTabRect(int Item, TRect & Rect)
{
  if (Item == TabIndex)
  {
    // Countered in CloseButtonRect
    Rect.Inflate(2, 2);
    Rect.Bottom--;
  }
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::ItemContentsRect(int Item, TRect & Rect)
{
  bool Selected = (Item == TabIndex);

  Rect.Left += 6;
  Rect.Top += 2;

  if (Selected)
  {
    Rect.Bottom -= 2;
    Rect.Top += 1;
  }
  else
  {
    Rect.Bottom += 2;
    Rect.Top += 3;
  }
}
//----------------------------------------------------------------------------------------------------------
bool __fastcall TThemePageControl::HasItemImage(int Item)
{
  return (Images != NULL) && (Pages[Item]->ImageIndex >= 0);
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::ItemTextRect(int Item, TRect & Rect)
{
  if (HasItemImage(Item))
  {
    Rect.Left += Images->Width + 3;
  }
  else
  {
    Rect.Left -= 2;
  }
  Rect.Right -= 3;
  OffsetRect(&Rect, 0, ((Item == TabIndex) ? 0 : -2));
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::DrawCross(HDC DC, int Width, COLORREF Color, const TRect & Rect)
{
  HPEN Pen = CreatePen(PS_SOLID, Width, Color);
  HPEN OldPen = static_cast<HPEN>(SelectObject(DC, Pen));
  // To-and-back - to make both ends look the same
  MoveToEx(DC, Rect.Left, Rect.Bottom - 1, NULL);
  LineTo(DC, Rect.Right - 1, Rect.Top);
  LineTo(DC, Rect.Left, Rect.Bottom - 1);
  MoveToEx(DC, Rect.Left, Rect.Top, NULL);
  LineTo(DC, Rect.Right - 1, Rect.Bottom - 1);
  LineTo(DC, Rect.Left, Rect.Top);
  SelectObject(DC, OldPen);
  DeleteObject(Pen);
}
//----------------------------------------------------------------------------------------------------------
// draw tab item context: possible icon and text
void __fastcall TThemePageControl::DrawTabItem(
  HDC DC, int Item, TRect TabRect, TRect Rect, bool Selected, bool Shadowed)
{
  ItemContentsRect(Item, Rect);

  UnicodeString Text = Pages[Item]->Caption;

  if (HasItemImage(Item))
  {
    int Left;
    if (!Text.IsEmpty())
    {
      Left = Rect.Left + (Selected ? 2 : 0);
    }
    else
    {
      Left = (Rect.Right - Images->Width - Rect.Left) / 2;
    }
    int Y = ((Rect.Top + Rect.Bottom - Images->Height) / 2) - 1 + (Selected ? 0 : -2);
    std::unique_ptr<TCanvas> Canvas(new TCanvas());
    Canvas->Handle = DC;
    Images->Draw(Canvas.get(), Left, Y, Pages[Item]->ImageIndex, !Shadowed);
  }

  int TextHeight = 20;
  int OldMode = SetBkMode(DC, TRANSPARENT);
  if (!Text.IsEmpty())
  {
    ItemTextRect(Item, Rect);
    HFONT OldFont = (HFONT)SelectObject(DC, Font->Handle);
    wchar_t * Buf = new wchar_t[Text.Length() + 1 + 4];
    wcscpy(Buf, Text.c_str());
    TRect TextRect(0, 0, Rect.Right - Rect.Left, TextHeight);
    // Truncates too long texts with ellipsis
    ::DrawText(DC, Buf, -1, &TextRect, DT_CALCRECT | DT_SINGLELINE | DT_MODIFYSTRING | DT_END_ELLIPSIS);

    DrawText(DC, Buf, -1, &Rect, DT_NOPREFIX | DT_CENTER);
    delete[] Buf;

    if (HasTabCloseButton(Item))
    {
      Rect = CloseButtonRect(Item);
      Rect.Offset(-TabRect.Left, -TabRect.Top);

      if (FHotCloseButton == Item)
      {
        HBRUSH Brush = CreateSolidBrush(GetSelectedBodyColor());
        FillRect(DC, &Rect, Brush);
        DeleteObject(Brush);

        HPEN Pen = CreatePen(PS_SOLID, 1, ColorToRGB(clHighlight));
        HPEN OldPen = static_cast<HPEN>(SelectObject(DC, Pen));
        Rectangle(DC, Rect.Left, Rect.Top, Rect.Right, Rect.Bottom);
        SelectObject(DC, OldPen);
        DeleteObject(Pen);
      }

      int CrossPadding = GetCrossPadding();

      COLORREF BackColor = GetPixel(DC, Rect.Left + (Rect.Width() / 2), Rect.Top + (Rect.Height() / 2));
      COLORREF CrossColor = ColorToRGB(Font->Color);
      #define BlendValue(FN) (((4 * static_cast<int>(FN(BackColor))) + static_cast<int>(FN(CrossColor))) / 5)
      COLORREF BlendColor = RGB(BlendValue(GetRValue), BlendValue(GetGValue), BlendValue(GetBValue));
      #undef BlendValue

      TRect CrossRect(Rect);
      CrossRect.Inflate(-CrossPadding, -CrossPadding);

      int CrossWidth = ScaleByTextHeight(this, 1);
      DrawCross(DC, CrossWidth + 1, BlendColor, CrossRect);
      DrawCross(DC, CrossWidth, CrossColor, CrossRect);
    }

    SelectObject(DC, OldFont);
  }

  SetBkMode(DC, OldMode);
}
//----------------------------------------------------------------------------------------------------------
int __fastcall TThemePageControl::CloseButtonSize()
{
  return ScaleByTextHeight(this, 16);
}
//----------------------------------------------------------------------------------------------------------
int __fastcall TThemePageControl::GetCrossPadding()
{
  return ScaleByTextHeight(this, 4);
}
//----------------------------------------------------------------------------------------------------------
TRect __fastcall TThemePageControl::CloseButtonRect(int Index)
{
  TRect Rect = TabRect(Index);
  ItemTabRect(Index, Rect);
  ItemContentsRect(Index, Rect);
  ItemTextRect(Index, Rect);

  int ACloseButtonSize = CloseButtonSize();
  int CrossPadding = GetCrossPadding();

  TEXTMETRIC TextMetric;
  Canvas->Font = Font;
  GetTextMetrics(Canvas->Handle, &TextMetric);

  Rect.Top += TextMetric.tmAscent - ACloseButtonSize + CrossPadding;
  Rect.Left = Rect.Right - ACloseButtonSize - ScaleByTextHeight(this, 1);
  if (Index == TabIndex)
  {
    // To counter Inflate(2, 2) in ItemTabRect
    Rect.Left -= 2;
  }
  Rect.Right = Rect.Left + ACloseButtonSize;
  Rect.Bottom = Rect.Top + ACloseButtonSize;
  return Rect;
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::SetHotCloseButton(int Index)
{
  if (Index != FHotCloseButton)
  {
    if (FHotCloseButton >= 0)
    {
      InvalidateTab(FHotCloseButton);
    }
    FHotCloseButton = Index;
    if (FHotCloseButton >= 0)
    {
      InvalidateTab(FHotCloseButton);
    }
  }
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::MouseMove(TShiftState /*Shift*/, int X, int Y)
{
  SetHotCloseButton(IndexOfCloseButtonAt(X, Y));
}
//----------------------------------------------------------------------------------------------------------
int __fastcall TThemePageControl::IndexOfCloseButtonAt(int X, int Y)
{
  int Result = IndexOfTabAt(X, Y);
  if ((Result < 0) ||
      !HasTabCloseButton(Result) ||
      !CloseButtonRect(Result).Contains(TPoint(X, Y)))
  {
    Result = -1;
  }
  return Result;
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::DrawThemesPart(HDC DC, int PartId,
  int StateId, LPCWSTR PartNameID, LPRECT Rect)
{
  HTHEME Theme = OpenThemeData(NULL, PartNameID);
  if (Theme != 0)
  {
    DrawThemeBackground(Theme, DC, PartId, StateId, Rect, NULL);
    CloseThemeData(Theme);
  }
}
//----------------------------------------------------------------------------------------------------------
bool __fastcall TThemePageControl::CanChange()
{
  FOldTabIndex = ActivePageIndex;

  return TPageControl::CanChange();
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::InvalidateTab(int Index)
{
  if (HandleAllocated())
  {
    TRect Rect = TabRect(Index);
    if (Index == TabIndex)
    {
      Rect.Inflate(2, 2);
    }
    // Original code was invalidating range against parent window
    // (recalculating coordinates first)
    InvalidateRect(Handle, &Rect, true);
  }
}
//----------------------------------------------------------------------------------------------------------
void __fastcall TThemePageControl::Change()
{
  // note that TabIndex yields correct value already here,
  // while ActivePageIndex is not updated yet
  if ((FOldTabIndex >= 0) && (FOldTabIndex != TabIndex) && UseThemes())
  {
    InvalidateTab(FOldTabIndex);
  }

  TPageControl::Change();
}
//----------------------------------------------------------------------------------------------------------
UnicodeString __fastcall TThemePageControl::FormatCaptionWithCloseButton(const UnicodeString & Caption)
{
  int OrigWidth = Canvas->TextWidth(Caption);
  UnicodeString Result = Caption;
  int CloseButtonWidth = CloseButtonSize();
  while (Canvas->TextWidth(Result) < OrigWidth + CloseButtonWidth)
  {
    Result += L" ";
  }
  return Result;
}
//---------------------------------------------------------------------------
void __fastcall TThemePageControl::WMLButtonDown(TWMLButtonDown & Message)
{
  int Index = IndexOfCloseButtonAt(Message.XPos, Message.YPos);
  if (Index >= 0)
  {
    Message.Result = 1;
    if (FOnCloseButtonClick != NULL)
    {
      FOnCloseButtonClick(this, Index);
    }
  }
  else
  {
    TPageControl::Dispatch(&Message);
  }
}
//---------------------------------------------------------------------------
void __fastcall TThemePageControl::Dispatch(void * Message)
{
  TMessage * M = reinterpret_cast<TMessage*>(Message);
  if (M->Msg == CM_MOUSELEAVE)
  {
    SetHotCloseButton(-1);
    TPageControl::Dispatch(Message);
  }
  else if (M->Msg == WM_LBUTTONDOWN)
  {
    WMLButtonDown(*reinterpret_cast<TWMLButtonDown *>(M));
  }
  else
  {
    TPageControl::Dispatch(Message);
  }
}
//----------------------------------------------------------------------------------------------------------
#ifdef _DEBUG
void __fastcall TThemePageControl::RequestAlign()
{
  TPageControl::RequestAlign();
}
#endif
//----------------------------------------------------------------------------------------------------------