| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: include/wx/vscroll.h |
| 3 | // Purpose: wxVScrolledWindow: generalization of wxScrolledWindow |
| 4 | // Author: Vadim Zeitlin |
| 5 | // Modified by: |
| 6 | // Created: 30.05.03 |
| 7 | // RCS-ID: $Id$ |
| 8 | // Copyright: (c) 2003 Vadim Zeitlin <vadim@wxwidgets.org> |
| 9 | // Licence: wxWindows licence |
| 10 | ///////////////////////////////////////////////////////////////////////////// |
| 11 | |
| 12 | #ifndef _WX_VSCROLL_H_ |
| 13 | #define _WX_VSCROLL_H_ |
| 14 | |
| 15 | #include "wx/panel.h" // base class |
| 16 | |
| 17 | // ---------------------------------------------------------------------------- |
| 18 | // wxVScrolledWindow |
| 19 | // ---------------------------------------------------------------------------- |
| 20 | |
| 21 | /* |
| 22 | In the name of this class, "V" may stand for "variable" because it can be |
| 23 | used for scrolling lines of variable heights; "virtual" because it is not |
| 24 | necessary to know the heights of all lines in advance -- only those which |
| 25 | are shown on the screen need to be measured; or, even, "vertical" because |
| 26 | this class only supports scrolling in one direction currently (this could |
| 27 | and probably will change in the future however). |
| 28 | |
| 29 | In any case, this is a generalization of the wxScrolledWindow class which |
| 30 | can be only used when all lines have the same height. It lacks some other |
| 31 | wxScrolledWindow features however, notably it currently lacks support for |
| 32 | horizontal scrolling; it can't scroll another window nor only a rectangle |
| 33 | of the window and not its entire client area. |
| 34 | */ |
| 35 | class WXDLLEXPORT wxVScrolledWindow : public wxPanel |
| 36 | { |
| 37 | public: |
| 38 | // constructors and such |
| 39 | // --------------------- |
| 40 | |
| 41 | // default ctor, you must call Create() later |
| 42 | wxVScrolledWindow() { Init(); } |
| 43 | |
| 44 | // normal ctor, no need to call Create() after this one |
| 45 | // |
| 46 | // note that wxVSCROLL is always automatically added to our style, there is |
| 47 | // no need to specify it explicitly |
| 48 | wxVScrolledWindow(wxWindow *parent, |
| 49 | wxWindowID id = wxID_ANY, |
| 50 | const wxPoint& pos = wxDefaultPosition, |
| 51 | const wxSize& size = wxDefaultSize, |
| 52 | long style = 0, |
| 53 | const wxString& name = wxPanelNameStr) |
| 54 | { |
| 55 | Init(); |
| 56 | |
| 57 | (void)Create(parent, id, pos, size, style, name); |
| 58 | } |
| 59 | |
| 60 | // same as the previous ctor but returns status code: true if ok |
| 61 | // |
| 62 | // just as with the ctor above, wxVSCROLL style is always used, there is no |
| 63 | // need to specify it |
| 64 | bool Create(wxWindow *parent, |
| 65 | wxWindowID id = wxID_ANY, |
| 66 | const wxPoint& pos = wxDefaultPosition, |
| 67 | const wxSize& size = wxDefaultSize, |
| 68 | long style = 0, |
| 69 | const wxString& name = wxPanelNameStr) |
| 70 | { |
| 71 | return wxPanel::Create(parent, id, pos, size, style | wxVSCROLL, name); |
| 72 | } |
| 73 | |
| 74 | |
| 75 | // operations |
| 76 | // ---------- |
| 77 | |
| 78 | // set the number of lines the window contains: the derived class must |
| 79 | // provide the heights for all lines with indices up to the one given here |
| 80 | // in its OnGetLineHeight() |
| 81 | void SetLineCount(size_t count); |
| 82 | |
| 83 | // scroll to the specified line: it will become the first visible line in |
| 84 | // the window |
| 85 | // |
| 86 | // return true if we scrolled the window, false if nothing was done |
| 87 | bool ScrollToLine(size_t line); |
| 88 | |
| 89 | // scroll by the specified number of lines/pages |
| 90 | virtual bool ScrollLines(int lines); |
| 91 | virtual bool ScrollPages(int pages); |
| 92 | |
| 93 | // redraw the specified line |
| 94 | virtual void RefreshLine(size_t line); |
| 95 | |
| 96 | // redraw all lines in the specified range (inclusive) |
| 97 | virtual void RefreshLines(size_t from, size_t to); |
| 98 | |
| 99 | // return the item at the specified (in physical coordinates) position or. |
| 100 | |
| 101 | // wxNOT_FOUND if none, i.e. if it is below the last item |
| 102 | int HitTest(wxCoord x, wxCoord y) const; |
| 103 | int HitTest(const wxPoint& pt) const { return HitTest(pt.x, pt.y); } |
| 104 | |
| 105 | // recalculate all our parameters and redisplay all lines |
| 106 | virtual void RefreshAll(); |
| 107 | |
| 108 | |
| 109 | // accessors |
| 110 | // --------- |
| 111 | |
| 112 | // get the number of lines this window contains (previously set by |
| 113 | // SetLineCount()) |
| 114 | size_t GetLineCount() const { return m_lineMax; } |
| 115 | |
| 116 | // get the first currently visible line |
| 117 | size_t GetVisibleBegin() const { return m_lineFirst; } |
| 118 | |
| 119 | // get the first currently visible line |
| 120 | size_t GetVisibleEnd() const { return m_lineFirst + m_nVisible; } |
| 121 | |
| 122 | // is this line currently visible? |
| 123 | bool IsVisible(size_t line) const |
| 124 | { return line >= GetVisibleBegin() && line < GetVisibleEnd(); } |
| 125 | |
| 126 | |
| 127 | // this is the same as GetVisibleBegin(), exists to match |
| 128 | // GetLastVisibleLine() and for backwards compatibility only |
| 129 | size_t GetFirstVisibleLine() const { return m_lineFirst; } |
| 130 | |
| 131 | // get the last currently visible line |
| 132 | // |
| 133 | // this function is unsafe as it returns (size_t)-1 (i.e. a huge positive |
| 134 | // number) if the control is empty, use GetVisibleEnd() instead, this one |
| 135 | // is kept for backwards compatibility |
| 136 | size_t GetLastVisibleLine() const { return GetVisibleEnd() - 1; } |
| 137 | |
| 138 | |
| 139 | protected: |
| 140 | // this function must be overridden in the derived class and it should |
| 141 | // return the height of the given line in pixels |
| 142 | virtual wxCoord OnGetLineHeight(size_t n) const = 0; |
| 143 | |
| 144 | // this function doesn't have to be overridden but it may be useful to do |
| 145 | // it if calculating the lines heights is a relatively expensive operation |
| 146 | // as it gives the user code a possibility to calculate several of them at |
| 147 | // once |
| 148 | // |
| 149 | // OnGetLinesHint() is normally called just before OnGetLineHeight() but you |
| 150 | // shouldn't rely on the latter being called for all lines in the interval |
| 151 | // specified here. It is also possible that OnGetLineHeight() will be |
| 152 | // called for the lines outside of this interval, so this is really just a |
| 153 | // hint, not a promise. |
| 154 | // |
| 155 | // finally note that lineMin is inclusive, while lineMax is exclusive, as |
| 156 | // usual |
| 157 | virtual void OnGetLinesHint(size_t WXUNUSED(lineMin), |
| 158 | size_t WXUNUSED(lineMax)) const { } |
| 159 | |
| 160 | // when the number of lines changes, we try to estimate the total height |
| 161 | // of all lines which is a rather expensive operation in terms of lines |
| 162 | // access, so if the user code may estimate the average height |
| 163 | // better/faster than we do, it should override this function to implement |
| 164 | // its own logic |
| 165 | // |
| 166 | // this function should return the best guess for the total height it may |
| 167 | // make |
| 168 | virtual wxCoord EstimateTotalHeight() const; |
| 169 | |
| 170 | |
| 171 | // the event handlers |
| 172 | void OnSize(wxSizeEvent& event); |
| 173 | void OnScroll(wxScrollWinEvent& event); |
| 174 | #if wxUSE_MOUSEWHEEL |
| 175 | void OnMouseWheel(wxMouseEvent& event); |
| 176 | #endif |
| 177 | |
| 178 | // find the index of the line we need to show at the top of the window such |
| 179 | // that the last (fully or partially) visible line is the given one |
| 180 | size_t FindFirstFromBottom(size_t lineLast, bool fullyVisible = false); |
| 181 | |
| 182 | // get the total height of the lines between lineMin (inclusive) and |
| 183 | // lineMax (exclusive) |
| 184 | wxCoord GetLinesHeight(size_t lineMin, size_t lineMax) const; |
| 185 | |
| 186 | // update the thumb size shown by the scrollbar |
| 187 | void UpdateScrollbar(); |
| 188 | |
| 189 | private: |
| 190 | // common part of all ctors |
| 191 | void Init(); |
| 192 | |
| 193 | |
| 194 | // the total number of (logical) lines |
| 195 | size_t m_lineMax; |
| 196 | |
| 197 | // the total (estimated) height |
| 198 | wxCoord m_heightTotal; |
| 199 | |
| 200 | // the first currently visible line |
| 201 | size_t m_lineFirst; |
| 202 | |
| 203 | // the number of currently visible lines (including the last, possibly only |
| 204 | // partly, visible one) |
| 205 | size_t m_nVisible; |
| 206 | |
| 207 | // accumulated mouse wheel rotation |
| 208 | #if wxUSE_MOUSEWHEEL |
| 209 | int m_sumWheelRotation; |
| 210 | #endif |
| 211 | |
| 212 | DECLARE_EVENT_TABLE() |
| 213 | DECLARE_NO_COPY_CLASS(wxVScrolledWindow) |
| 214 | DECLARE_ABSTRACT_CLASS(wxVScrolledWindow) |
| 215 | }; |
| 216 | |
| 217 | #endif // _WX_VSCROLL_H_ |
| 218 | |