src/add-ons/screen_savers/haiku/ScreenSaver.cpp

   1 /*
   2 **
   3 ** A simple screensaver, displays the text "Haiku" at random locations.
   4 **
   5 ** Version: 3.0
   6 **
   7 ** Copyright (c) 2002, 2005 Marcus Overhagen. All Rights Reserved.
   8 ** This file may be used under the terms of the MIT License.
   9 */
  10
  11
  12 #include <stdlib.h>
  13
  14 #include <Catalog.h>
  15 #include <DefaultSettingsView.h>
  16 #include <Font.h>
  17 #include <ScreenSaver.h>
  18 #include <StringView.h>
  19 #include <View.h>
  20
  21
  22 #undef B_TRANSLATION_CONTEXT
  23 #define B_TRANSLATION_CONTEXT "Screensaver Haiku"
  24
  25
  26 class ScreenSaver : public BScreenSaver
  27 {
  28 public:
  29                                 ScreenSaver(BMessage *archive, image_id);
  30         void            Draw(BView *view, int32 frame);
  31         void            StartConfig(BView *view);
  32         status_t        StartSaver(BView *view, bool preview);
  33
  34 private:
  35         const char *fText;
  36         float           fX;
  37         float           fY;
  38         float           fSizeX;
  39         float           fSizeY;
  40         float           fTextHeight;
  41         float           fTextWith;
  42         bool            fIsPreview;
  43 };
  44
  45
  46 BScreenSaver *instantiate_screen_saver(BMessage *msg, image_id image)
  47 {
  48         return new ScreenSaver(msg, image);
  49 }
  50
  51
  52 ScreenSaver::ScreenSaver(BMessage *archive, image_id id)
  53  :      BScreenSaver(archive, id)
  54  ,      fText("Haiku")
  55  ,      fX(0)
  56  ,      fY(0)
  57 {
  58 }
  59
  60
  61 void
  62 ScreenSaver::StartConfig(BView *view)
  63 {
  64         BPrivate::BuildDefaultSettingsView(view, "Haiku",
  65                 B_TRANSLATE("by Marcus Overhagen"));
  66 }
  67
  68
  69 status_t
  70 ScreenSaver::StartSaver(BView *view, bool preview)
  71 {
  72         // save view dimensions and preview mode
  73         fIsPreview = preview;
  74         fSizeX = view->Bounds().Width();
  75         fSizeY = view->Bounds().Height();
  76
  77         // set a new font, about 1/8th of view height, and bold
  78         BFont font;
  79         view->GetFont(&font);
  80         font.SetSize(fSizeY / 8);
  81         font.SetFace(B_BOLD_FACE);
  82         view->SetFont(&font);
  83
  84         // find out space needed for text display
  85         BRect rect;
  86         escapement_delta delta;
  87         delta.nonspace = 0;
  88         delta.space = 0;
  89         font.GetBoundingBoxesForStrings(&fText, 1, B_SCREEN_METRIC, &delta, &rect);
  90         fTextHeight = rect.Height();
  91         fTextWith = rect.Width();
  92
  93         // seed the random number generator
  94         srand((int)system_time());
  95
  96         return B_OK;
  97 }
  98
  99
 100 void
 101 ScreenSaver::Draw(BView *view, int32 frame)
 102 {
 103         if (frame == 0) {
 104                 // fill with black on first frame
 105                 view->SetLowColor(0, 0, 0);
 106                 view->FillRect(view->Bounds(), B_SOLID_LOW);
 107         } else {
 108                 // erase old text on all other frames
 109                 view->SetHighColor(0, 0, 0);
 110                 view->DrawString(fText, BPoint(fX, fY));
 111         }
 112
 113         // find some new text coordinates
 114         fX = rand() % int(fSizeX - fTextWith);
 115         fY = rand() % int(fSizeY - fTextHeight - (fIsPreview ? 2 : 20)) + fTextHeight;
 116
 117         // draw new text
 118         view->SetHighColor(0, 255, 0);
 119         view->DrawString(fText, BPoint(fX, fY));
 120
 121         // randomize time until next update (preview mode is faster)
 122         SetTickSize(((rand() % 4) + 1) * (fIsPreview ? 300000 : 1000000));
 123 }