ref: 0e529f14089be1db45e4747df5f774d7d63035ce
dir: /textscreen/txt_scrollpane.c/
// // Copyright(C) 2005-2014 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. // #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 = FullHeight(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; } if (scrollpane->child != NULL) { if (scrollpane->child->w < scrollpane->w) { scrollpane->child->w = scrollpane->w; } if (scrollpane->child->h < scrollpane->h) { scrollpane->child->h = scrollpane->h; } } } static void TXT_ScrollPaneDrawer(TXT_UNCAST_ARG(scrollpane)) { 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); } // 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); } } static void TXT_ScrollPaneFocused(TXT_UNCAST_ARG(scrollpane), int focused) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); // Whether the child is focused depends only on whether the scroll pane // itself is focused. Pass through focus to the child. if (scrollpane->child != NULL) { TXT_SetWidgetFocus(scrollpane->child, focused); } } // 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); } } // Another hack for tables - when scrolling in 'pages', the normal key press // event does not provide children with enough information to know how far // to move their selection to reach a new page. This function does so. // Note that it *only* affects scrolling in pages, not with arrows! // A side-effect of this, rather than 'pulling' the selection to fit within // the new page, is that we will jump straight over ranges of unselectable // items longer than a page, but that is also true of arrow-key scrolling. // The other unfortunate effect of doing things this way is that page keys // have no effect on tables _not_ in scrollpanes: not even home/end. static int PageSelectedWidget(txt_scrollpane_t *scrollpane, int key) { int pagex = 0; // No page left/right yet, but some keyboards have them int pagey = 0; // Subtract one from the absolute page distance as this is slightly more // intuitive: a page down first jumps to the bottom of the current page, // then proceeds to scroll onwards. switch (key) { case KEY_PGUP: pagey = 1 - scrollpane->h; break; case KEY_PGDN: pagey = scrollpane->h - 1; break; default: // We shouldn't even be in this function return 0; } if (scrollpane->child->widget_class == &txt_table_class) { return TXT_PageTable(scrollpane->child, pagex, pagey); } return 0; } // Interpret arrow key presses as scroll commands static int InterpretScrollKey(txt_scrollpane_t *scrollpane, int key) { int maxy; 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; case KEY_PGUP: if (scrollpane->y > 0) { scrollpane->y -= scrollpane->h; if (scrollpane->y < 0) { scrollpane->y = 0; } return 1; } break; case KEY_PGDN: maxy = FullHeight(scrollpane) - scrollpane->h; if (scrollpane->y < maxy) { scrollpane->y += scrollpane->h; if (scrollpane->y > maxy) { scrollpane->y = maxy; } 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 ((key == KEY_UPARROW || key == KEY_DOWNARROW || key == KEY_LEFTARROW || key == KEY_RIGHTARROW || key == KEY_PGUP || key == KEY_PGDN || key == KEY_TAB) && scrollpane->child->widget_class == &txt_table_class) { if (PageSelectedWidget(scrollpane, key)) { result = 1; } 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); if (b == TXT_MOUSE_SCROLLUP) { if (scrollbars & SCROLLBAR_VERTICAL) { scrollpane->y -= 3; } else if (scrollbars & SCROLLBAR_HORIZONTAL) { scrollpane->x -= 3; } return; } else if (b == TXT_MOUSE_SCROLLDOWN) { if (scrollbars & SCROLLBAR_VERTICAL) { scrollpane->y += 3; } else if (scrollbars & SCROLLBAR_HORIZONTAL) { scrollpane->x += 3; } return; } 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; int bar_max = scrollpane->w - 3; scrollpane->x = ((rel_x - 1) * range + bar_max - 1) / bar_max; } return; } // Click on the vertical 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; int bar_max = scrollpane->h - 3; scrollpane->y = ((rel_y - 1) * range + bar_max - 1) / bar_max; } 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); } } static int TXT_ScrollPaneSelectable(TXT_UNCAST_ARG(scrollpane)) { TXT_CAST_ARG(txt_scrollpane_t, scrollpane); // If scroll bars are displayed, the scroll pane must be selectable // so that we can use the arrow keys to scroll around. if (NeedsScrollbars(scrollpane)) { return 1; } // Otherwise, whether this is selectable depends on the child widget. return TXT_SelectableWidget(scrollpane->child); } txt_widget_class_t txt_scrollpane_class = { TXT_ScrollPaneSelectable, TXT_ScrollPaneSizeCalc, TXT_ScrollPaneDrawer, TXT_ScrollPaneKeyPress, TXT_ScrollPaneDestructor, TXT_ScrollPaneMousePress, TXT_ScrollPaneLayout, TXT_ScrollPaneFocused, }; 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; // Set parent pointer for inner widget. target->parent = &scrollpane->widget; return scrollpane; }