ref: f6ce7dfea99cf32beb2afc8e7b02fb5f19f7544f
dir: /textscreen/txt_scrollpane.c/
// Emacs style mode select -*- C++ -*- //----------------------------------------------------------------------------- // // Copyright(C) 2009 Simon Howard // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License // as published by the Free Software Foundation; either version 2 // of the License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA // 02111-1307, USA. // #include <ctype.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include "txt_scrollpane.h" #include "txt_gui.h" #include "txt_io.h" #include "txt_main.h" #include "txt_table.h" #include "doomkeys.h" #define SCROLLBAR_VERTICAL (1 << 0) #define SCROLLBAR_HORIZONTAL (1 << 1) static int FullWidth(txt_scrollpane_t *scrollpane) { if (scrollpane->child != NULL) { return scrollpane->child->w; } else { return 0; } } static int FullHeight(txt_scrollpane_t *scrollpane) { if (scrollpane->child != NULL) { return scrollpane->child->h; } else { return 0; } } // Calculate which scroll bars the pane needs. static int NeedsScrollbars(txt_scrollpane_t *scrollpane) { int result; result = 0; if (FullWidth(scrollpane) > scrollpane->w) { result |= SCROLLBAR_HORIZONTAL; } if (FullHeight(scrollpane) > scrollpane->h) { result |= SCROLLBAR_VERTICAL; } return result; } // If a scrollbar isn't needed, the scroll position is reset. static void SanityCheckScrollbars(txt_scrollpane_t *scrollpane) { int scrollbars; int max_x, max_y; scrollbars = NeedsScrollbars(scrollpane); if ((scrollbars & SCROLLBAR_HORIZONTAL) == 0) { scrollpane->x = 0; } if ((scrollbars & SCROLLBAR_VERTICAL) == 0) { scrollpane->y = 0; } max_x = FullWidth(scrollpane) - scrollpane->w; max_y = FullHeight(scrollpane) - scrollpane->h; if (scrollpane->x < 0) { scrollpane->x = 0; } else if (scrollpane->x > max_x) { scrollpane->x = max_x; } if (scrollpane->y < 0) { scrollpane->y = 0; } else if (scrollpane->y > max_y) { scrollpane->y = max_y; } } static void TXT_ScrollPaneSizeCalc(TXT_UNCAST_ARG(scrollpane)) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); int scrollbars; if (scrollpane->child != NULL) { TXT_CalcWidgetSize(scrollpane->child); } // Expand as necessary (to ensure that no scrollbars are needed)? if (scrollpane->expand_w) { scrollpane->w = FullWidth(scrollpane); } if (scrollpane->expand_h) { scrollpane->h = FullWidth(scrollpane); } scrollpane->widget.w = scrollpane->w; scrollpane->widget.h = scrollpane->h; // If we have scroll bars, we need to expand slightly to // accomodate them. Eg. if we have a vertical scrollbar, we // need to be an extra character wide. scrollbars = NeedsScrollbars(scrollpane); if (scrollbars & SCROLLBAR_HORIZONTAL) { ++scrollpane->widget.h; } if (scrollbars & SCROLLBAR_VERTICAL) { ++scrollpane->widget.w; } } static void TXT_ScrollPaneDrawer(TXT_UNCAST_ARG(scrollpane), int selected) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); int x1, y1, x2, y2; int scrollbars; // We set a clipping area of the scroll pane. x1 = scrollpane->widget.x, y1 = scrollpane->widget.y, x2 = x1 + scrollpane->w, y2 = y1 + scrollpane->h; scrollbars = NeedsScrollbars(scrollpane); if (scrollbars & SCROLLBAR_HORIZONTAL) { TXT_DrawHorizScrollbar(x1, y1 + scrollpane->h, scrollpane->w, scrollpane->x, FullWidth(scrollpane) - scrollpane->w); } if (scrollbars & SCROLLBAR_VERTICAL) { TXT_DrawVertScrollbar(x1 + scrollpane->w, y1, scrollpane->h, scrollpane->y, FullHeight(scrollpane) - scrollpane->h); } TXT_PushClipArea(x1, x2, y1, y2); // Draw the child widget if (scrollpane->child != NULL) { TXT_DrawWidget(scrollpane->child, selected); } // Restore old clipping area. TXT_PopClipArea(); } static void TXT_ScrollPaneDestructor(TXT_UNCAST_ARG(scrollpane)) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); if (scrollpane->child != NULL) { TXT_DestroyWidget(scrollpane->child); } } // Hack for tables - when browsing a table inside a scroll pane, // automatically scroll the window to show the newly-selected // item. static void ShowSelectedWidget(txt_scrollpane_t *scrollpane) { txt_widget_t *selected; selected = TXT_GetSelectedWidget(scrollpane->child); // Scroll up or down? if (selected->y <= scrollpane->widget.y) { scrollpane->y -= scrollpane->widget.y - selected->y; } else if ((signed) (selected->y + selected->h) > (signed) (scrollpane->widget.y + scrollpane->h)) { scrollpane->y += (selected->y + selected->h) - (scrollpane->widget.y + scrollpane->h); } // Scroll left or right? if (selected->x <= scrollpane->widget.x) { scrollpane->x -= scrollpane->widget.x - selected->x; } else if ((signed) (selected->x + selected->w) > (signed) (scrollpane->widget.x + scrollpane->w)) { scrollpane->x += (selected->x + selected->w) - (scrollpane->widget.x + scrollpane->w); } } // Interpret arrow key presses as scroll commands static int InterpretScrollKey(txt_scrollpane_t *scrollpane, int key) { switch (key) { case KEY_UPARROW: if (scrollpane->y > 0) { --scrollpane->y; return 1; } break; case KEY_DOWNARROW: if (scrollpane->y < FullHeight(scrollpane) - scrollpane->h) { ++scrollpane->y; return 1; } break; case KEY_LEFTARROW: if (scrollpane->x > 0) { --scrollpane->x; return 1; } break; case KEY_RIGHTARROW: if (scrollpane->x < FullWidth(scrollpane) - scrollpane->w) { ++scrollpane->x; return 1; } break; default: break; } return 0; } static int TXT_ScrollPaneKeyPress(TXT_UNCAST_ARG(scrollpane), int key) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); int result; result = 0; if (scrollpane->child != NULL) { result = TXT_WidgetKeyPress(scrollpane->child, key); // Gross hack - if we're scrolling in a menu with the keyboard, // automatically move the scroll pane to show the new // selected item. if (scrollpane->child->widget_class == &txt_table_class && (key == KEY_UPARROW || key == KEY_DOWNARROW || key == KEY_LEFTARROW || key == KEY_RIGHTARROW)) { ShowSelectedWidget(scrollpane); } // If the child widget didn't use the keypress, we can see // if it can be interpreted as a scrolling command. if (result == 0) { result = InterpretScrollKey(scrollpane, key); } } return result; } static void TXT_ScrollPaneMousePress(TXT_UNCAST_ARG(scrollpane), int x, int y, int b) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); int scrollbars; int rel_x, rel_y; scrollbars = NeedsScrollbars(scrollpane); rel_x = x - scrollpane->widget.x; rel_y = y - scrollpane->widget.y; // Click on the horizontal scrollbar? if ((scrollbars & SCROLLBAR_HORIZONTAL) && rel_y == scrollpane->h) { if (rel_x == 0) { --scrollpane->x; } else if (rel_x == scrollpane->w - 1) { ++scrollpane->x; } else { int range = FullWidth(scrollpane) - scrollpane->w; scrollpane->x = ((rel_x - 1) * range) / (scrollpane->w - 3); } return; } // Click on the horizontal scrollbar? if ((scrollbars & SCROLLBAR_VERTICAL) && rel_x == scrollpane->w) { if (rel_y == 0) { --scrollpane->y; } else if (rel_y == scrollpane->h - 1) { ++scrollpane->y; } else { int range = FullHeight(scrollpane) - scrollpane->h; scrollpane->y = ((rel_y - 1) * range) / (scrollpane->h - 3); } return; } if (scrollpane->child != NULL) { TXT_WidgetMousePress(scrollpane->child, x, y, b); } } static void TXT_ScrollPaneLayout(TXT_UNCAST_ARG(scrollpane)) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); SanityCheckScrollbars(scrollpane); // The child widget takes the same position as the scroll pane // itself, but is offset by the scroll position. if (scrollpane->child != NULL) { scrollpane->child->x = scrollpane->widget.x - scrollpane->x; scrollpane->child->y = scrollpane->widget.y - scrollpane->y; TXT_LayoutWidget(scrollpane->child); } } txt_widget_class_t txt_scrollpane_class = { TXT_ScrollPaneSizeCalc, TXT_ScrollPaneDrawer, TXT_ScrollPaneKeyPress, TXT_ScrollPaneDestructor, TXT_ScrollPaneMousePress, TXT_ScrollPaneLayout, }; txt_scrollpane_t *TXT_NewScrollPane(int w, int h, TXT_UNCAST_ARG(target)) { TXT_CAST_ARG(txt_widget_t, target); txt_scrollpane_t *scrollpane; scrollpane = malloc(sizeof(txt_scrollpane_t)); TXT_InitWidget(scrollpane, &txt_scrollpane_class); scrollpane->w = w; scrollpane->h = h; scrollpane->x = 0; scrollpane->y = 0; scrollpane->child = target; scrollpane->expand_w = w <= 0; scrollpane->expand_h = h <= 0; return scrollpane; }