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commit e4d8b941025fcdd232e748227634529f752381b7
Author: Albrecht Schlosser <albrechts.fltk@online.de>
AuthorDate: Sun Nov 7 00:20:44 2021 +0100
Commit: Albrecht Schlosser <albrechts.fltk@online.de>
CommitDate: Mon Nov 15 14:41:31 2021 +0100
Add fl_draw_check() to draw better check marks (issue #68)
This new function can and should be used to draw check marks
in widgets that need it, e.g. Fl_Check_Browser (issue #68) and
Fl_Check_Button.
FL/fl_draw.H | 13 ++++--
src/Fl_Check_Browser.cxx | 15 +++----
src/Fl_Light_Button.cxx | 43 ++++++++++++-------
src/fl_draw.cxx | 108 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 151 insertions(+), 28 deletions(-)
diff --git FL/fl_draw.H FL/fl_draw.H
index 9e2e4b3..3d3a544 100644
--- FL/fl_draw.H
+++ FL/fl_draw.H
@@ -1,7 +1,7 @@
//
// Portable drawing function header file for the Fast Light Tool Kit (FLTK).
//
-// Copyright 1998-2020 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
@@ -22,8 +22,9 @@
#ifndef fl_draw_H
#define fl_draw_H
-#include <FL/Enumerations.H> // for the color names
-#include <FL/Fl_Graphics_Driver.H> // for fl_graphics_driver + Fl_Region
+#include <FL/Enumerations.H> // color names
+#include <FL/Fl_Graphics_Driver.H> // fl_graphics_driver + Fl_Region
+#include <FL/Fl_Rect.H>
// Image class...
class Fl_Image;
@@ -749,10 +750,16 @@ FL_EXPORT void fl_draw(const char* str, int x, int y, int w, int h,
Fl_Image* img=0, int draw_symbols = 1);
// boxtypes:
+
FL_EXPORT void fl_frame(const char* s, int x, int y, int w, int h);
FL_EXPORT void fl_frame2(const char* s, int x, int y, int w, int h);
FL_EXPORT void fl_draw_box(Fl_Boxtype, int x, int y, int w, int h, Fl_Color);
+// basic GUI objects (check marks, arrows, more to come ...):
+
+// Draw a check mark in the given color inside the bounding box bb.
+void fl_draw_check(Fl_Rect bb, Fl_Color col);
+
// images:
/**
diff --git src/Fl_Check_Browser.cxx src/Fl_Check_Browser.cxx
index 3b32731..a05c4e4 100644
--- src/Fl_Check_Browser.cxx
+++ src/Fl_Check_Browser.cxx
@@ -184,20 +184,17 @@ void Fl_Check_Browser::item_draw(void *v, int X, int Y, int, int) const {
int cy = Y + (tsize + 1 - CHECK_SIZE) / 2;
X += 2;
+ // draw the check mark box (always)
fl_color(active_r() ? FL_FOREGROUND_COLOR : fl_inactive(FL_FOREGROUND_COLOR));
fl_loop(X, cy, X, cy + CHECK_SIZE,
X + CHECK_SIZE, cy + CHECK_SIZE, X + CHECK_SIZE, cy);
+
+ // draw the check mark
if (i->checked) {
- int tx = X + 3;
- int tw = CHECK_SIZE - 4;
- int d1 = tw / 3;
- int d2 = tw - d1;
- int ty = cy + (CHECK_SIZE + d2) / 2 - d1 - 2;
- for (int n = 0; n < 3; n++, ty++) {
- fl_line(tx, ty, tx + d1, ty + d1);
- fl_line(tx + d1, ty + d1, tx + tw - 1, ty + d1 - d2 + 1);
- }
+ fl_draw_check(Fl_Rect(X + 1, cy + 1, CHECK_SIZE - 1, CHECK_SIZE - 1), fl_color());
}
+
+ // draw the item text
fl_font(textfont(), tsize);
if (i->selected) {
col = fl_contrast(col, selection_color());
diff --git src/Fl_Light_Button.cxx src/Fl_Light_Button.cxx
index 4de85bc..71064d9 100644
--- src/Fl_Light_Button.cxx
+++ src/Fl_Light_Button.cxx
@@ -32,11 +32,15 @@ void Fl_Light_Button::draw() {
Fl_Color col = value() ? (active_r() ? selection_color() :
fl_inactive(selection_color())) : color();
- int W = labelsize();
+ int W = labelsize(); // check mark box size
+ if (W > 25) W = 25; // limit box size
int bx = Fl::box_dx(box()); // box frame width
- int dx = bx + 2; // relative position of check mark etc.
+ int dx = bx + 2; // relative position of check mark box
int dy = (h() - W) / 2; // neg. offset o.k. for vertical centering
int lx = 0; // relative label position (STR #3237)
+ int cx = x() + dx; // check mark box x-position
+ int cy = y() + dy; // check mark box y-position
+ int cw = 0; // check mark box width and height
if (down_box()) {
// draw other down_box() styles:
@@ -46,22 +50,17 @@ void Fl_Light_Button::draw() {
case _FL_PLASTIC_DOWN_BOX :
case _FL_PLASTIC_UP_BOX :
// Check box...
- draw_box(down_box(), x()+dx, y()+dy, W, W, FL_BACKGROUND2_COLOR);
+ draw_box(down_box(), cx, cy, W, W, FL_BACKGROUND2_COLOR);
if (value()) {
+ // Check mark...
if (Fl::is_scheme("gtk+")) {
- fl_color(FL_SELECTION_COLOR);
- } else {
- fl_color(col);
- }
- int tx = x() + dx + 3;
- int tw = W - 6;
- int d1 = tw/3;
- int d2 = tw-d1;
- int ty = y() + dy + (W+d2)/2-d1-2;
- for (int n = 0; n < 3; n++, ty++) {
- fl_line(tx, ty, tx+d1, ty+d1);
- fl_line(tx+d1, ty+d1, tx+tw-1, ty+d1-d2+1);
+ col = FL_SELECTION_COLOR;
}
+ // Calculate box position and size
+ cx += Fl::box_dx(down_box());
+ cy += Fl::box_dy(down_box());
+ cw = W - Fl::box_dw(down_box());
+ fl_draw_check(Fl_Rect(cx, cy, cw, cw), col);
}
break;
case _FL_ROUND_DOWN_BOX :
@@ -149,7 +148,19 @@ int Fl_Light_Button::handle(int event) {
/**
Creates a new Fl_Light_Button widget using the given
position, size, and label string.
- <P>The destructor deletes the check button.
+
+ The default box type is \p FL_UP_BOX and the default down box
+ type down_box() is \p FL_NO_BOX (0).
+
+ The selection_color() sets the color of the "light".
+ Default is FL_YELLOW.
+
+ The default label alignment is \p 'FL_ALIGN_LEFT|FL_ALIGN_INSIDE' so
+ the label is drawn inside the button area right of the "light".
+
+ \note Do not change the default box types of Fl_Light_Button. The
+ box types determine how the button is drawn. If you change the
+ down_box() type the drawing behavior is undefined.
*/
Fl_Light_Button::Fl_Light_Button(int X, int Y, int W, int H, const char* l)
: Fl_Button(X, Y, W, H, l) {
diff --git src/fl_draw.cxx src/fl_draw.cxx
index ba33db9..efa7a14 100644
--- src/fl_draw.cxx
+++ src/fl_draw.cxx
@@ -475,3 +475,111 @@ float fl_override_scale() {
void fl_restore_scale(float s) {
fl_graphics_driver->restore_scale(s);
}
+
+/**
+ Draw a check mark inside the given bounding box.
+
+ The check mark is allowed to fill the entire box but the algorithm used
+ makes sure that a 1-pixel border is kept free if the box is large enough.
+ You need to calculate margins for box borders etc. yourself.
+
+ The check mark size is limited (minimum and maximum size) and the check
+ mark is always centered in the given box.
+
+ \note If the box is too small (bad GUI design) the check mark will be drawn
+ over the box borders. This is intentional for better user experience.
+ Otherwise users might not be able to recognize if a box is checked.
+
+ The size limits are implementation details and may be changed at any time.
+
+ \param[in] X,Y top left corner of the bounding box
+ \param[in] W,H width and height of the bounding box
+
+ \since 1.4.0
+*/
+
+void fl_draw_check(Fl_Rect bb, Fl_Color col) {
+
+ const int md = 6; // max. d1 value: 3 * md + 1 pixels wide
+ int tx = bb.x();
+ int ty = bb.y();
+ int tw = bb.w();
+ int th = bb.h();
+ int lh = 3; // line height 3 means 4 pixels
+ int d1, d2;
+
+ Fl_Color saved_color = fl_color();
+
+ // make sure there's a free 1-pixel border if the area is large enough
+ if (tw > 10) {
+ tx++;
+ tw -= 2;
+ }
+ if (th > 10) {
+ ty++;
+ th -= 2;
+ }
+ // calculate d1, the width and height of the left part of the check mark
+ d1 = tw / 3;
+ d2 = 2 * d1;
+ if (d1 > md) {
+ d1 = md;
+ d2 = 2 * d1;
+ }
+ // make sure the height fits
+ if (d2 + lh + 1 > th) {
+ d2 = th - lh - 1;
+ d1 = (d2+1) / 2;
+ }
+ // check minimal size (box too small)
+ if (d1 < 2) {
+ d1 = 2;
+ d2 = 4;
+ }
+ // reduce line height (width) for small sizes
+ if (d1 < 4)
+ lh = 2;
+
+ tw = d1 + d2 + 1; // total width
+ th = d2 + lh + 1; // total height
+
+ tx = bb.x() + (bb.w() - tw + 1) / 2; // x position (centered)
+ ty = bb.y() + (bb.h() - th + 1) / 2; // y position (centered)
+
+ // Set DEBUG_FRAME to 1 - 3 for debugging (0 otherwise)
+ // Bit 1 set: draws a green background (the entire given box)
+ // Bit 2 set: draws a red frame around the check mark (the bounding box)
+ // The background (1) can be used to test correct positioning by the widget code
+
+#define DEBUG_FRAME (3)
+#if (DEBUG_FRAME)
+ if (DEBUG_FRAME & 1) { // 1 = background
+ fl_color(0x88dd8800);
+ fl_rectf(bb.x(), bb.y(), bb.w(), bb.h());
+ }
+ if (DEBUG_FRAME & 2) { // 2 = bounding box
+ fl_color(0xff000000);
+ fl_rect(tx, ty, tw, th);
+ }
+#endif
+
+ // draw the check mark
+
+ fl_color(col);
+
+ fl_begin_complex_polygon();
+
+ ty += d2 - d1; // upper border of check mark: left to right
+ fl_vertex(tx, ty);
+ fl_vertex(tx + d1, ty + d1);
+ fl_vertex(tx + d1 + d2, ty + d1 - d2);
+ ty += lh; // lower border of check mark: right to left
+ fl_vertex(tx + d1 + d2, ty + d1 - d2);
+ fl_vertex(tx + d1, ty + d1);
+ fl_vertex(tx, ty);
+
+ fl_end_complex_polygon();
+
+ fl_color(saved_color);
+
+} // fl_draw_check()
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