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transparentpad.C
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1 /// \file
2 /// \ingroup tutorial_cocoa
3 /// This macro demonstrates semi-transparent pads.
4 /// Requires OS X and ROOT configured with --enable-cocoa.
5 ///
6 /// \macro_code
7 ///
8 /// \author Timur Pocheptsov
9 
10 //Includes for ACLiC (cling does not need them).
11 #include "TVirtualX.h"
12 #include "TCanvas.h"
13 #include "TError.h"
14 #include "TColor.h"
15 #include "TH1F.h"
16 
17 //Aux. functions for tutorials/cocoa.
18 #include "customcolor.h"
19 
20 void transparentpad()
21 {
22  //1. Try to 'allocate' free indices for our custom colors -
23  //we can use hard-coded indices like 1001, 1002, 1003 ... but
24  //I prefer to find free indices in a ROOT's color table
25  //to avoid possible conflicts with other tutorials.
26  Color_t indices[3] = {};
28  ::Error("transparentpad", "failed to create new custom colors");
29  return;
30  }
31 
32  //2. Create a TCanvas to force a gVirtualX initialization.
33  TCanvas * const c1 = new TCanvas("transparent pad","transparent pad demo", 10, 10, 900, 500);
34  //We can check gVirtualX (its type):
35  if (gVirtualX && !gVirtualX->InheritsFrom("TGCocoa")) {
36  ::Warning("transparentpad", "You can see the transparency ONLY in a pdf or png output (\"File\"->\"Save As\" ->...)\n"
37  "To have transparency in a canvas graphics, you need OS X version with cocoa enabled");
38  }
39 
40  //2. Create special transparent colors.
41  new TColor(indices[0], 1., 0.2, 0.2, "transparent_pink", 0.25);
42  new TColor(indices[1], 0.2, 1., 0.2, "transparent_green", 0.25);
43  new TColor(indices[2], 0.2, 2., 1., "transparent_blue", 0.15);
44 
45  //3. Some arbitrary histograms.
46  TH1F * const h1 = new TH1F("TH1F 1", "TH1F 1", 100, -1.5, 1.5);
47  h1->FillRandom("gaus");
48 
49  TH1F * const h2 = new TH1F("TH1F 2", "TH1F 2", 100, -1.5, 0.);
50  h2->FillRandom("gaus");
51 
52  TH1F * const h3 = new TH1F("TH1F 3", "TH1F 3", 100, 0.5, 2.);
53  h3->FillRandom("landau");
54 
55  //4. Now overlapping transparent pads.
56  TPad * const pad1 = new TPad("transparent pad 1", "transparent pad 1", 0.1, 0.1, 0.7, 0.7);
57  pad1->SetFillColor(indices[0]);//here's the magic!
58  pad1->cd();
59  h1->Draw("lego2");
60  c1->cd();
61  pad1->Draw();
62 
63  TPad * const pad2 = new TPad("transparent pad 2", "transparent pad 2", 0.2, 0.2, 0.8, 0.8);
64  pad2->SetFillColor(indices[1]);//here's the magic!
65  pad2->cd();
66  h2->Draw();
67  c1->cd();
68  pad2->Draw();
69 
70  TPad * const pad3 = new TPad("transparent pad 3", "transparent pad 3", 0.3, 0.3, 0.9, 0.9);
71  pad3->SetFillColor(indices[2]);//here's the magic!
72  pad3->cd();
73  h3->Draw();
74  c1->cd();
75  pad3->Draw();
76 }
77 
TH1F.h
Warning
void Warning(const char *location, const char *msgfmt,...)
Use this function in warning situations.
Definition: TError.cxx:231
TPad
Definition: TPad.h:26
gVirtualX
#define gVirtualX
Definition: TVirtualX.h:338
TColor.h
TVirtualX.h
TCanvas.h
ROOT::CocoaTutorials::FindFreeCustomColorIndices
unsigned FindFreeCustomColorIndices(Color_t(&indices)[N])
Definition: customcolor.h:38
Color_t
short Color_t
Definition: RtypesCore.h:83
h1
TH1F * h1
Definition: legend1.C:5
TColor
Definition: TColor.h:19
customcolor.h
TH1::FillRandom
virtual void FillRandom(const char *fname, Int_t ntimes=5000)
Fill histogram following distribution in function fname.
Definition: TH1.cxx:3444
TCanvas
Definition: TCanvas.h:23
TH1F
1-D histogram with a float per channel (see TH1 documentation)}
Definition: TH1.h:572
TPad::cd
TVirtualPad * cd(Int_t subpadnumber=0)
Set Current pad.
Definition: TPad.cxx:594
TH1::Draw
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition: TH1.cxx:2997
Error
void Error(const char *location, const char *msgfmt,...)
Use this function in case an error occurred.
Definition: TError.cxx:187
TError.h
c1
return c1
Definition: legend1.C:41
TPad::Draw
virtual void Draw(Option_t *option="")
Draw Pad in Current pad (re-parent pad if necessary).
Definition: TPad.cxx:1285