tvplanit: Extend TVpGanttView such that it can be painted only over a given date interval.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8480 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/tvplanit/source/vpganttview.pas

@@ -89,8 +89,10 @@ type
     FActiveDate: TDateTime;  // Selected date
     FFirstDate: TDateTime;   // Date of the first event in the resource
     FLastDate: TDateTime;    // Date of the last event in the resource
-    FStartDate: TDateTime;   // Date of the first event to be displayed/printed
+    FStartDate: TDateTime;   // Date of the first event to be displayed/printed (0 = first event ever)
-    FEndDate: TDateTime;     // Date of the last event to be displayed/printed
+    FEndDate: TDateTime;     // Date of the last event to be displayed/printed (0 = last event ever)
+    FRealStartDate: TDate;   // Date of the first event to be displayed/printed (0 replaced)
+    FRealEndDate: TDate;     // Date of the last event to be displayed/printed (0 repalaced)
 
     FLeftCol: Integer;       // Index of the left-most day column
     FTopRow: Integer;        // Index of the top-most event row
@@ -181,10 +183,11 @@ type
     function GetDateTimeAtCoord(X: Integer): TDateTime;
     function GetEventAtCoord(X, Y: Integer): TVpEvent;
     function GetEventOfRow(ARow: Integer): TVpEvent;
+    procedure GetRealEventDateRange(out AStartDate, AEndDate: TDate);
     function GetRowAtCoord(Y: Integer): Integer;
     function GetRowOfEvent(AEvent: TVpEvent): Integer;
-    procedure GetEventDateRange;
+    procedure GetEventDateRange(out AFirstDate, ALastDate: TDate);
-    function IsEventOnDate(AEvent: TVpEvent; ADate: TDateTime): Boolean;
+    function IsEventOnDate(AEvent: TVpEvent; ADate: TDate): Boolean;
     procedure Hookup;
     procedure Populate;
     procedure PopulateDayRecords;
@@ -251,6 +254,7 @@ type
       Angle: TVpRotationAngle; Scale: Extended; RenderDate: TDateTime;
       StartLine, StopLine: Integer; UseGran: TVpGranularity;
       DisplayOnly: Boolean); override;
+    procedure SetDateLimits(AStartDate, AEndDate: TDateTime);
 
     {$IF VP_LCL_SCALING = 2}
     procedure FixDesignFontsPPI(const ADesignTimePPI: Integer); override;
@@ -261,16 +265,18 @@ type
     {$ENDIF}
     {$ENDIF}
 
-    // Methods to be called by painter
+    // Methods/properties used by painter. Not meant to be called by user.
     function CalcVisibleCols(AWidth, AFixedColWidth, AColWidth: Integer): Integer;
     function CalcVisibleRows(AHeight, AHeaderHeight, ARowHeight: Integer): Integer;
+    property FirstDate: TDateTime read FFirstDate;
+    property LastDate: TDateTime read FLastDate;
+    property RealStartDate: TDateTime read FRealStartDate;
+    property RealEndDate: TDateTime read FRealEndDate;
 
     property ActiveCol: Integer read FActiveCol write SetActiveCol;
     property ActiveEvent: TVpEvent read FActiveEvent write SetActiveEvent;
     property ActiveDate: TDateTime read FActiveDate write SetActiveDate;
     property ActiveRow: Integer read FActiveRow write SetActiveRow;
-    property FirstDate: TDateTime read FFirstDate;
-    property LastDate: TDateTime read FLastDate;
     property StartDate: TDateTime read FStartDate write FStartDate;
     property EndDate: TDateTime read FEndDate write FEndDate;
     property ColCount: Integer read FColCount write FColCount;
@@ -502,7 +508,7 @@ begin
   if UseAsHint then begin
     { Usage as hint }
     startDateStr := FormatDateTime(DATE_FORMAT, AEvent.StartTime);
-    if trunc(AEvent.StartTime) = trunc(AEvent.EndTime) then
+    if SameDate(AEvent.StartTime, AEvent.EndTime) then
       endDateStr := ''
     else
       endDateStr := FormatDateTime(DATE_FORMAT, AEvent.EndTime);
@@ -612,9 +618,7 @@ var
   dt, startTime, endTime: TDateTime;
 begin
   inherited;
-//  dvClickTimer.Enabled := false;
   FMouseDown := false;
-  //FDragging := false;
 
   // If the mouse was pressed down in the client area, then select the cell.
   if not Focused then
@@ -626,15 +630,18 @@ begin
     exit;
   end;
 
+  // Is there an event at the clicked cell?
   FActiveEvent := GetEventAtCoord(FMouseDownPoint.X, FMouseDownPoint.Y);
   if (FActiveEvent <> nil) then
+    // yes: edit the event
     SpawnEventEditDialog(False)
   else
   begin
+    // no: add a new event
     dt := GetDateTimeAtCoord(FMouseDownPoint.X);
     if dt <> NO_DATE then
     begin
-      startTime := trunc(dt);
+      startTime := DatePart(dt);
       endTime := startTime + 1.0;
       ActiveEvent := Datastore.Resource.Schedule.AddEvent(
         Datastore.GetNextID(EventsTableName),
@@ -645,33 +652,6 @@ begin
     end;
   end;
   FMouseDownPoint := Point(0, 0);
-
-      (*
-
-  if (Msg.XPos > dvRowHeadWidth - 9) and (Msg.YPos > dvColHeadHeight) then
-  begin
-    { The mouse click landed inside the client area }
-    dvSetActiveRowByCoord(Point(Msg.XPos, Msg.YPos), True);
-    { See if we hit an active event }
-    if (FActiveEvent <> nil) and (not ReadOnly) then begin
-      { edit this event }
-      dvSpawnEventEditDialog(False);
-    end else if not ReadOnly then begin
-      if not CheckCreateResource then
-        Exit;
-      if (DataStore = nil) or (DataStore.Resource = nil) then
-        Exit;
-      { otherwise, we must want to create a new event }
-      StartTime := trunc(FDisplayDate + ActiveCol)
-        + dvLineMatrix[ActiveCol, ActiveRow].Time;
-      EndTime := StartTime + dvTimeIncSize * FRowLinesStep;
-      FActiveEvent := DataStore.Resource.Schedule.AddEvent(
-        DataStore.GetNextID(EventsTableName), StartTime, EndTime);
-      { edit this new event }
-      dvSpawnEventEditDialog(True);
-    end;
-  end;
-  *)
 end;
 
 procedure TVpGanttView.DeleteActiveEvent(Prompt: Boolean);
@@ -786,7 +766,7 @@ end;
 
 function TVpGanttView.GetDateOfCol(ACol: Integer): TDateTime;
 begin
-  Result := FStartDate + ACol;
+  Result := FRealStartDate + ACol;
 end;
 
 function TVpGanttView.GetDateTimeAtCoord(X: Integer): TDateTime;
@@ -795,7 +775,7 @@ var
 begin
   days := (X - FixedColWidth) / FColWidth + FLeftCol;
   if (days >= 0) and (days < NumDays) then
-    Result := FStartDate + days
+    Result := FRealStartDate + days
   else
     Result := NO_DATE;
 end;
@@ -827,7 +807,7 @@ begin
     Result := eventRec.Event;
     if Result.AllDayEvent then
     begin
-      if (dt < trunc(Result.StartTime)) or (dt > trunc(Result.EndTime) + 1) then
+      if (dt < DatePart(Result.StartTime)) or (dt > DatePart(Result.EndTime) + 1) then
         Result := nil;
     end else
       if (dt < Result.StartTime) or (dt > Result.EndTime) then
@@ -837,8 +817,8 @@ end;
 
 { Determines the date when the earliest event starts, and the date when the
   latest event ends.
-  Stores them in the internal variables FStartdate and FEndDate. }
+  Stores them in the internal variables FFirstDate and FLastDate. }
-procedure TVpGanttView.GetEventDateRange;
+procedure TVpGanttView.GetEventDateRange(out AFirstDate, ALastDate: TDate);
 var
   i: Integer;
   event: TVpEvent;
@@ -851,20 +831,15 @@ begin
   end else
   begin
     event := Datastore.Resource.Schedule.GetEvent(0);
-    FFirstDate := trunc(event.StartTime);
+    FFirstDate := DatePart(event.StartTime);
     FLastDate := -99999;
     for i := 0 to Datastore.Resource.Schedule.EventCount-1 do
     begin
       event := Datastore.Resource.Schedule.GetEvent(i);
-      d := trunc(event.EndTime);
+      d := DatePart(event.EndTime);
       if d > FLastDate then FLastDate := d;
     end;
   end;
-
-  if FStartDate = 0 then
-    FStartDate := FFirstDate;
-  if FEndDate = 0 then
-    FEndDate := FLastDate;
 end;
 
 function TVpGanttView.GetEventOfRow(ARow: Integer): TVpEvent;
@@ -882,12 +857,12 @@ begin
   Result := FMonthRecords[AIndex];
 end;
 
-{ Determines the number days between the first and last Gantt event. This is
+{ Determines the number of days between the first and last Gantt event. This is
   the number of day columns in the view. }
 function TVpGanttView.GetNumDays: Integer;
 begin
-  if (FStartDate <> NO_DATE) then
+  if (FRealStartDate <> NO_DATE) then
-    Result := trunc(FEndDate) - trunc(FStartDate) + 1
+    Result := trunc(FRealEndDate) - trunc(FRealStartDate) + 1
   else
     Result := 0;
 end;
@@ -895,10 +870,7 @@ end;
 { Determines the number of events (= rows) to be displayed in the GanttView. }
 function TVpGanttView.GetNumEvents: Integer;
 begin
-  if (Datastore <> nil) and (Datastore.Resource <> nil) then
+  Result := Length(FEventRecords);
-    Result := Datastore.Resource.Schedule.EventCount
-  else
-    Result := 0;
 end;
 
 { Determines the number of months (complete or partial) between the first and
@@ -908,10 +880,10 @@ var
   y1, m1, d1: Word;
   y2, m2, d2: Word;
 begin
-  if (FStartDate <> NO_DATE) then
+  if (FRealStartDate <> NO_DATE) then
   begin
-    DecodeDate(FStartDate, y1, m1, d1);
+    DecodeDate(FRealStartDate, y1, m1, d1);
-    DecodeDate(FEndDate, y2, m2, d2);
+    DecodeDate(FRealEndDate, y2, m2, d2);
     if (y1 = y2) then
       Result := m2 - m1 + 1
     else
@@ -920,6 +892,15 @@ begin
     Result := 0;
 end;
 
+{ Calculates the first and last date to be displayed in the GanttView. This
+  is necessary because the properties StartDate and EndDate may be 0 which
+  means the very first/last event. }
+procedure TVpGanttView.GetRealEventDateRange(out AStartDate, AEndDate: TDate);
+begin
+  if FStartDate > 0 then AStartDate := DatePart(FStartDate) else AStartDate := FFirstDate;
+  if FEndDate > 0 then AEndDate := DatePart(FEndDate) else AEndDate := FLastDate;
+end;
+
 function TVpGanttView.GetRowAtCoord(Y: Integer): Integer;
 begin
   Result := (Y - FTotalColHeaderHeight) div FRowHeight + FTopRow;
@@ -958,7 +939,8 @@ begin
   CalcRowHeight;
   CalcColHeaderHeight;
 
-  GetEventDateRange;
+  GetEventDateRange(FFirstDate, FLastDate);
+  GetRealEventDateRange(FRealStartDate, FRealEndDate);
   FColCount := GetNumDays;
   FRowCount := GetNumEvents;
 
@@ -966,16 +948,18 @@ begin
   PopulateMonthRecords;
   PopulateEventRecords;
 end;
-
+{ Checks whether the specified date belongs to the specified event.
-function TVpGanttView.IsEventOnDate(AEvent: TVpEvent; ADate: TDateTime): Boolean;
+  The function returns true if the event begins before or at the date and ends
+  at or after it. }
+function TVpGanttView.IsEventOnDate(AEvent: TVpEvent; ADate: TDate): Boolean;
 var
-  tEv1, tEv2: TDateTime;
+  dEv1, dEv2: TDate;
 begin
   if AEvent <> nil then
   begin
-    tEv1 := trunc(AEvent.StartTime);
+    dEv1 := DatePart(AEvent.StartTime);
-    tEv2 := trunc(AEvent.EndTime);
+    dEv2 := DatePart(AEvent.EndTime);
-    Result := (tEv1 <= ADate) and (tEv2 >= ADate);
+    Result := (dEv1 <= ADate) and (ADate <= dEv2);
   end else
     Result := false;
 end;
@@ -1188,7 +1172,7 @@ begin
     Rect(0, 0, Width, Height),   // Paint Rectangle
     ra0,                         // Rotation angle: none
     1,                           // Scale
-    FStartDate,                  // Date
+    FActiveDate,                 // Date
     -1,                          // Start At
     -1,                          // End At
     gr30Min,                     // Granularity
@@ -1219,7 +1203,7 @@ begin
   begin
     x2 := x1 + ColWidth;
     FDayRecords[i].Rect := Rect(x1, y1, x2, y2);
-    FDayRecords[i].Date := FStartDate + i;
+    FDayRecords[i].Date := FRealStartDate + i;
     x1 := x2;
   end;
 end;
@@ -1233,37 +1217,54 @@ var
   totalWidth: Integer;
   list: TFPList;
 begin
-  SetLength(FEventRecords, GetNumEvents);
   if (Datastore = nil) or (DataStore.Resource = nil) then
     exit;
 
   list := TFPList.Create;
   try
-    // Sort events by date/time
+    // Consider only events which are, fully or partly, inside the
+    // displayed date range between FRealStartDate and FRealEndDate
     for i := 0 to Datastore.Resource.Schedule.EventCount-1 do
-      list.Add(Datastore.Resource.Schedule.GetEvent(i));
+    begin
+      event := Datastore.Resource.Schedule.GetEvent(i);
+      if DatePart(event.EndTime) < FRealStartDate then
+        continue;
+      if DatePart(event.StartTime) > FRealEndDate then
+        continue;
+      list.Add(event);
+    end;
+
+    // Sort events by date/time - this is a general requirement for Gantt
     list.Sort(@CompareEvents);
 
+    // Prepare array for the event records simplifying work for the Gantt view
+    SetLength(FEventRecords, list.Count);
+
+    // Iterate over all considered events, fill the event record and store it
+    // in the array
     xh1 := 0;
     xh2 := FixedColWidth;
     y1 := FTotalColHeaderHeight;
     totalWidth := GetNumDays * ColWidth;
-    for i := 0 to High(FEventRecords) do
+    for i := 0 to list.Count-1 do
     begin
       event := TVpEvent(list[i]);
+
+      // The time range of events reaching out of the displayed date range
+      // must be clipped at the edges.
+      t1 := IfThen(event.StartTime >= FRealStartDate, event.StartTime, FRealStartDate);
+      t2 := IfThen(event.EndTime <= FRealEndDate + 1, event.EndTime, FRealEndDate + 1);
       if event.AllDayEvent then
       begin
-        t1 := trunc(event.StartTime);
+        t1 := DatePart(t1);
-        t2 := trunc(event.EndTime) + 1;
+        t2 := DatePart(t2) + 1;
-        if frac(event.EndTime) = 0 then t2 := t2 + 1;
+        if TimePart(t2) = 0 then t2 := t2 + 1;
-      end else
-      begin
-        t1 := event.StartTime;
-        t2 := event.EndTime;
       end;
+
+      // Store event, caption and its rectangle coordinates in the EventRec
       y2 := y1 + FRowHeight;
-      xe1 := round((t1 - FStartDate) / numDays * totalWidth) + FixedColWidth;
+      xe1 := round((t1 - FRealStartDate) / numDays * totalWidth) + FixedColWidth;
-      xe2 := round((t2 - FStartDate) / numDays * totalWidth) + FixedColWidth;
+      xe2 := round((t2 - FRealStartDate) / numDays * totalWidth) + FixedColWidth;
       if xe1 = xe2 then xe2 := xe1 + 1;
       FEventRecords[i].Event := event;
       FEventRecords[i].Caption := event.Description;
@@ -1297,7 +1298,8 @@ begin
 
   if n > 1 then
   begin
-    dm := FStartDate;
+    // Date interval crosses one or more month boundaries
+    dm := FRealStartDate;
     for i := 0 to n - 1 do
     begin
       if i = 0 then begin
@@ -1305,11 +1307,11 @@ begin
         dm := StartOfTheMonth(dm);
       end else
       if i = n-1 then
-        nDays := DayOf(FEndDate)
+        nDays := DayOf(FRealEndDate)
       else
         nDays := DaysInMonth(dm);
-      if dm + nDays > FEndDate then
+      if dm + nDays > FRealEndDate then
-        nDays := trunc(FEndDate) - trunc(dm) + 1;
+        nDays := trunc(FRealEndDate) - trunc(dm) + 1;
       x2 := x1 + nDays * ColWidth;
       FMonthRecords[i].Rect := Rect(x1, y1, x2, y2);
       FMonthRecords[i].Date := dm;
@@ -1318,10 +1320,11 @@ begin
     end;
   end else
   begin
-    nDays := DayOf(FEndDate) - DayOf(FStartDate) + 1;
+    // Date interval is within the same month
+    nDays := DayOf(FRealEndDate) - DayOf(FRealStartDate) + 1;
     x2 := x1 + nDays * ColWidth;
     FMonthRecords[0].Rect := Rect(x1, y1, x2, y2);
-    FMonthRecords[0].Date := FStartDate;
+    FMonthRecords[0].Date := FRealStartDate;
   end;
 end;
 
@@ -1342,6 +1345,20 @@ begin
   end;
 end;
 
+procedure TVpGanttView.SetDateLimits(AStartDate, AEndDate: TDateTime);
+var
+  oldDate: TDateTime;
+begin
+  oldDate := FActiveDate;
+
+  FStartDate := AStartDate;
+  FEndDate := AEndDate;
+  Init;
+
+  FActiveDate := 0;
+  SetActiveDate(oldDate);
+end;
+
 {$IF VP_LCL_SCALING = 2}
 procedure TVpGanttView.FixDesignFontsPPI(const ADesignTimePPI: Integer);
 begin
@@ -1371,26 +1388,26 @@ end;
 
 procedure TVpGanttView.ScrollDateIntoView(ADate: TDateTime);
 begin
-  if (FStartDate = 0) or (FStartDate = NO_DATE) then
+  if (FRealStartDate = 0) or (FRealStartDate = NO_DATE) then
     exit;
 
-  if ADate < FStartDate then
+  if ADate < FRealStartDate then
   begin
-    FStartDate := trunc(ADate);
+    FRealStartDate := DatePart(ADate);
     FColCount := GetNumDays;
     SetLeftCol(-MaxInt);
   end else
-  if ADate > FEndDate then
+  if ADate > FRealEndDate then
   begin
-    FEndDate := trunc(ADate);
+    FRealEndDate := DatePart(ADate);
     FColCount := GetNumDays;
     SetLeftCol(FColCount - 1 - FVisibleCols);
   end else
-  if ADate < FStartDate + FLeftCol then
+  if ADate < FRealStartDate + FLeftCol then
-    SetLeftCol(trunc(ADate) - trunc(FStartDate))
+    SetLeftCol(trunc(ADate) - trunc(FRealStartDate))
   else
-  if ADate > FStartDate + VisibleCols then
+  if ADate > FRealStartDate + FVisibleCols then
-    SetLeftCol(trunc(ADate) - VisibleCols)
+    SetLeftCol(trunc(ADate) - FVisibleCols)
   else
     exit;
   Invalidate;
@@ -1446,14 +1463,14 @@ end;
 
 procedure TVpGanttView.SetActiveDate(AValue: TDateTime);
 begin
-  if FActiveDate <> trunc(AValue) then begin
+  if FActiveDate <> DatePart(AValue) then begin
-    FActiveDate := trunc(AValue);
+    FActiveDate := DatePart(AValue);
 
     if FLoaded then
       Populate;
 
     ScrollDateIntoView(FActiveDate);
-    FActiveCol := trunc(FActiveDate) - trunc(FStartDate);
+    FActiveCol := trunc(FActiveDate) - trunc(FRealStartDate);
     Invalidate;
 
     if (not FInLinkHandler) and (ControlLink <> nil) then
@@ -1871,7 +1888,7 @@ begin
     Exit;
 
   // Create the new event as an all-day event for the clicked day.
-  startTime := trunc(FActiveDate);
+  startTime := DatePart(FActiveDate);
   endTime := startTime + 1 - OneMilliSecond;
   FActiveEvent := DataStore.Resource.Schedule.AddEvent(
     DataStore.GetNextID(EventsTableName),

components/tvplanit/source/vpganttviewpainter.pas

@@ -333,6 +333,10 @@ begin
   begin
     eventRec := FGanttView.EventRecords[i];
     event := eventRec.Event;
+    if event.EndTime < FGanttView.FirstDate then
+      Continue;
+    if event.StartTime > FGanttView.LastDate then
+      exit;
     R := ScaleRect(eventRec.EventRect);
     OffsetRect(R, -dx, -dy);
     inc(R.Top, top_margin);
@@ -409,18 +413,17 @@ begin
       eventRec := FGanttView.EventRecords[numEvents-1];
       R := ScaleRect(eventRec.EventRect);
       y2 := R.Bottom - dy;
-    end else
+      n := FGanttView.NumDays;
-      y2 := RealBottom;
+      for i := 0 to n-1 do
-    n := FGanttView.NumDays;
-    for i := 0 to n-1 do
-    begin
-      dayRec := FGanttView.DayRecords[i];
-      R := ScaleRect(dayRec.Rect);
-      x1 := R.Right - dx;
-      if x1 >= FScaledFixedColWidth then
       begin
-        TPSMoveTo(RenderCanvas, Angle, RenderIn, x1, y1);
+        dayRec := FGanttView.DayRecords[i];
-        TPSLineTo(RenderCanvas, Angle, RenderIn, x1, y2)
+        R := ScaleRect(dayRec.Rect);
+        x1 := R.Right - dx;
+        if x1 >= FScaledFixedColWidth then
+        begin
+          TPSMoveTo(RenderCanvas, Angle, RenderIn, x1, y1);
+          TPSLineTo(RenderCanvas, Angle, RenderIn, x1, y2)
+        end;
       end;
     end;
   end;
@@ -507,7 +510,7 @@ var
 begin
   with FGanttView do
   begin
-    if (StartDate = NO_DATE) or (SpecialDayMode <> sdmColumn) then
+    if (RealStartDate = NO_DATE) or (SpecialDayMode <> sdmColumn) then
       exit;
 
     nEvents := NumEvents;
@@ -515,9 +518,13 @@ begin
     dx := LeftCol * FScaledColWidth;
     dy := TopRow * FScaledRowHeight;
 
-    R := ScaleRect(EventRecords[nEvents-1].HeadRect);
     y1 := RealTop + FScaledTotalColHeaderHeight;
-    y2 := R.Bottom - dy;
+    if nEvents > 0 then
+    begin
+      R := ScaleRect(EventRecords[nEvents-1].HeadRect);
+      y2 := R.Bottom - dy;
+    end else
+      y2 := y1;
 
     RenderCanvas.Brush.style := bsSolid;
     for i := 0 to nDays-1 do

components/tvplanit/source/vpmisc.pas

@@ -146,6 +146,9 @@ function DaysInAMonth(Year, Month: Integer): Integer;
   {-return the number of days in the specified month of a given year}
 {$ENDIF}{$ENDIF}
 
+function DatePart(ADateTime: TDateTime): TDateTime; inline;
+function TimePart(ADateTime: TDateTime): TDateTime; inline;
+
 function GetJulianDate(Date: TDateTime): Word;
 function GetWeekOfYear(ADate: TDateTime): byte;
 function IsWeekend(ADate: TDateTime): Boolean;
@@ -710,6 +713,16 @@ begin
 end;
 {$ENDIF}{$ENDIF}
 
+function DatePart(ADateTime: TDateTime): TDateTime;
+begin
+  Result := trunc(ADateTime);
+end;
+
+function TimePart(ADateTime: TDateTime): TDateTime;
+begin
+  Result := frac(ADateTime);
+end;
+
 function GetJulianDate(Date: TDateTime): Word;
 var
   y, m, d, I: word;