source/gui/IGUIScrollBar.cpp

   1 /* Copyright (C) 2015 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "precompiled.h"
  19
  20 #include "GUI.h"
  21 #include "maths/MathUtil.h"
  22
  23 IGUIScrollBar::IGUIScrollBar() : m_pStyle(NULL), m_pGUI(NULL),
  24                                                                  m_X(300.f), m_Y(300.f),
  25                                                                  m_ScrollRange(1.f), m_ScrollSpace(0.f), // MaxPos: not 0, due to division.
  26                                                                  m_Length(200.f), m_Width(20.f),
  27                                                                  m_BarSize(0.f), m_Pos(0.f),
  28                                                                  m_ButtonPlusPressed(false),
  29                                                                  m_ButtonMinusPressed(false),
  30                                                                  m_ButtonPlusHovered(false),
  31                                                                  m_ButtonMinusHovered(false),
  32                                                                  m_BarHovered(false),
  33                                                                  m_BarPressed(false)
  34 {
  35 }
  36
  37 IGUIScrollBar::~IGUIScrollBar()
  38 {
  39 }
  40
  41 void IGUIScrollBar::SetupBarSize()
  42 {
  43         if (!GetStyle())
  44                 return;
  45
  46         float min = GetStyle()->m_MinimumBarSize;
  47         float max = GetStyle()->m_MaximumBarSize;
  48         float length = m_Length;
  49
  50         // Check for edge buttons
  51         if (GetStyle()->m_UseEdgeButtons)
  52                 length -= GetStyle()->m_Width * 2.f;
  53
  54         // Check min and max are valid
  55         if (min > length)
  56                 min = 0.f;
  57         if (max < min)
  58                 max = length;
  59
  60         // Clamp size to not exceed a minimum or maximum.
  61         m_BarSize = clamp(length * std::min((float)m_ScrollSpace / (float)m_ScrollRange, 1.f), min, max);
  62 }
  63
  64 const SGUIScrollBarStyle* IGUIScrollBar::GetStyle() const
  65 {
  66         if (!m_pHostObject)
  67                 return NULL;
  68
  69         return m_pHostObject->GetScrollBarStyle(m_ScrollBarStyle);
  70 }
  71
  72 CGUI* IGUIScrollBar::GetGUI() const
  73 {
  74         if (!m_pHostObject)
  75                 return NULL;
  76
  77         return m_pHostObject->GetGUI();
  78 }
  79
  80 void IGUIScrollBar::UpdatePosBoundaries()
  81 {
  82         if (m_Pos < 0.f ||
  83                 m_ScrollRange < m_ScrollSpace) // <= scrolling not applicable
  84                 m_Pos = 0.f;
  85         else if (m_Pos > GetMaxPos())
  86                 m_Pos = GetMaxPos();
  87 }
  88
  89 void IGUIScrollBar::HandleMessage(SGUIMessage& Message)
  90 {
  91         switch (Message.type)
  92         {
  93         case GUIM_MOUSE_MOTION:
  94         {
  95                 // TODO Gee: Optimizations needed!
  96
  97                 CPos mouse = m_pHostObject->GetMousePos();
  98
  99                 // If bar is being dragged
 100                 if (m_BarPressed)
 101                 {
 102                         SetPosFromMousePos(mouse);
 103                         UpdatePosBoundaries();
 104                 }
 105
 106                 // check if components are being hovered
 107                 m_BarHovered = GetBarRect().PointInside(mouse);
 108                 m_ButtonMinusHovered = HoveringButtonMinus(mouse);
 109                 m_ButtonPlusHovered =  HoveringButtonPlus(mouse);
 110
 111                 if (!m_ButtonMinusHovered)
 112                         m_ButtonMinusPressed = false;
 113
 114                 if (!m_ButtonPlusHovered)
 115                         m_ButtonPlusPressed = false;
 116                 break;
 117         }
 118
 119         case GUIM_MOUSE_PRESS_LEFT:
 120         {
 121                 if (!m_pHostObject)
 122                         break;
 123
 124                 CPos mouse = m_pHostObject->GetMousePos();
 125
 126                 // if bar is pressed
 127                 if (GetBarRect().PointInside(mouse))
 128                 {
 129                         m_BarPressed = true;
 130                         m_BarPressedAtPos = mouse;
 131                         m_PosWhenPressed = m_Pos;
 132                 }
 133                 // if button-minus is pressed
 134                 else if (m_ButtonMinusHovered)
 135                 {
 136                         m_ButtonMinusPressed = true;
 137                         ScrollMinus();
 138                 }
 139                 // if button-plus is pressed
 140                 else if (m_ButtonPlusHovered)
 141                 {
 142                         m_ButtonPlusPressed = true;
 143                         ScrollPlus();
 144                 }
 145                 // Pressing the background of the bar, to scroll
 146                 //  notice the if-sentence alone does not admit that,
 147                 //  it must be after the above if/elses
 148                 else
 149                 {
 150                         if (GetOuterRect().PointInside(mouse))
 151                         {
 152                                 // Scroll plus or minus a lot, this might change, it doesn't
 153                                 //  have to be fancy though.
 154                                 if (mouse.y < GetBarRect().top)
 155                                         ScrollMinusPlenty();
 156                                 else
 157                                         ScrollPlusPlenty();
 158                                 // Simulate mouse movement to see if bar now is hovered
 159                                 SGUIMessage msg(GUIM_MOUSE_MOTION);
 160                                 HandleMessage(msg);
 161                         }
 162                 }
 163                 break;
 164         }
 165
 166         case GUIM_MOUSE_RELEASE_LEFT:
 167                 m_ButtonMinusPressed = false;
 168                 m_ButtonPlusPressed = false;
 169                 break;
 170
 171         case GUIM_MOUSE_WHEEL_UP:
 172         {
 173                 ScrollMinus();
 174                 // Since the scroll was changed, let's simulate a mouse movement
 175                 //  to check if scrollbar now is hovered
 176                 SGUIMessage msg(GUIM_MOUSE_MOTION);
 177                 HandleMessage(msg);
 178                 break;
 179         }
 180
 181         case GUIM_MOUSE_WHEEL_DOWN:
 182         {
 183                 ScrollPlus();
 184                 // Since the scroll was changed, let's simulate a mouse movement
 185                 //  to check if scrollbar now is hovered
 186                 SGUIMessage msg(GUIM_MOUSE_MOTION);
 187                 HandleMessage(msg);
 188                 break;
 189         }
 190
 191         default:
 192                 break;
 193         }
 194 }