forked from AuroraMiddleware/gtk
3d737ee8ba
Sat Nov 20 15:13:51 2004 Owen Taylor <otaylor@redhat.com> * gdk/gdkpango.[ch]: Add GdkPangoRenderer, a subclass of PangoRenderer targeting GDK drawables. Use to implement the old gdk_draw_layout() and friends. * gdk/gdkdraw.c gdk/gdkdrawable.h gdk/gdkwindow.c gdk/gdkpixmap.c: Add gdk_draw_glyphs_transformed() gdk_draw_trapezoids() and the corresponding members of GdkDrawableClass. Add a fallback implementation of gdk_draw_trapezoids() in terms of pixbufs. * gdk/gdkwindowing.h gdk/x11/gdkg-x11.h: Add _gdk_windowing_gc_get_foreground() to enable the fallback trapezoid implementation. * gdk/x11/gdkdrawable-x11.c gdk/x11/gdkdisplay-x11.h: Implement draw_glyph_transformed, draw_trapezoids. * gdk/x11/gdkdrawable-x11.[ch]: Add _gdk_x11_drawable_draw_xtrapezoids, _gdk_x11_drawable_draw_xft_glyphs for use of GdkX11Renderer. * gdk/x11/gdkgc-x11.c gdk/x11/gdkprivate-x11.h: Implement GDK_TILED, GDK_STIPPLED, GDK_OPAQUE_STIPPLED in the RENDER codepath. * gdk/gdkpango-x11.c: Add GdkX11Renderer... a subclass of PangoXftRenderer that does tiles/stipples and fallback rendering of trapezoids without the RENDER extension. * gdk/gdkpango-x11.c gdk/x11/gdkscreen-x11.[ch] _gdk_x11_renderer_get: Add _gdk_x11_renderer_get() to get a singleton GdkX11Renderer for the screen. * gdk/x11/gdkdrawable-x11.c (get_impl_drawable): Fix a None/NULL confusion. * gtk/gtklabel.[ch] gtk/gtk.symbols: Add gtk_label_set/get_angle(), and an ::angle property. * gtk/gtklabel.c: Remove #if 0'd dead code gtk_label_paint_word(). * gtk/gtktextdisplay.c: Switch to using a GtkTextRenderer subclass of GdkPangoRenderer for drawing. * gtk/gtktextlayout.[ch] gtk/gtktextdisplay.c: Switch to using gtk_attr_shape_new_with_data() to store backreferences to embedded pixmaps and widgets. Leave line_display->shaped_objects around for backwords compatibility. * gdk/gdkpango.[ch] (gdk_pango_context_set_colormap): Describe as deprecated, remove implementation. * gtk/gtkwidget.c (gtk_widget_create_pango_context): Remove call to gdk_pango_context_set_colormap. * demos/gtk-demo/Makefile.am demos/gtk-demo/rotated_text.c: Add a demo showing drawing rotated text. * tests/testgtk.c: Add a rotated-label test, and also a rotated drawing test (differs from demos/gtk-demo/rotated_text by also using a tile)
143 lines
4.8 KiB
C
143 lines
4.8 KiB
C
/* Rotated Text
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*
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* This demo shows how to use GDK and Pango to draw rotated and transformed
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* text. The use of GdkPangoRenderer in this example is a somewhat advanced
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* technique; most applications can simply use gdk_draw_layout(). We use
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* it here mostly because that allows us to work in user coordinates - that is,
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* coordinates prior to the application of the transformation matrix, rather
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* than device coordinates.
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*
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* As of GTK+-2.6, the ability to draw transformed and anti-aliased graphics
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* as shown in this example is only present for text. With GTK+-2.8, a new
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* graphics system called "Cairo" will be introduced that provides these
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* capabilities and many more for all types of graphics.
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*/
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#include <math.h>
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#include <gtk/gtk.h>
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static GtkWidget *window = NULL;
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static gboolean
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rotated_text_expose_event (GtkWidget *widget,
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GdkEventExpose *event,
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gpointer data)
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{
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#define RADIUS 150
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#define N_WORDS 10
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#define FONT "Sans Bold 27"
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PangoRenderer *renderer;
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PangoMatrix matrix = PANGO_MATRIX_INIT;
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PangoContext *context;
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PangoLayout *layout;
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PangoFontDescription *desc;
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int width = widget->allocation.width;
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int height = widget->allocation.height;
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double device_radius;
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int i;
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/* Get the default renderer for the screen, and set it up for drawing */
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renderer = gdk_pango_renderer_get_default (gtk_widget_get_screen (widget));
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gdk_pango_renderer_set_drawable (GDK_PANGO_RENDERER (renderer), widget->window);
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gdk_pango_renderer_set_gc (GDK_PANGO_RENDERER (renderer), widget->style->black_gc);
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/* Set up a transformation matrix so that the user space coordinates for
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* the centered square where we draw are [-RADIUS, RADIUS], [-RADIUS, RADIUS]
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* We first center, then change the scale */
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device_radius = MIN (width, height) / 2.;
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pango_matrix_translate (&matrix,
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device_radius + (width - 2 * device_radius) / 2,
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device_radius + (height - 2 * device_radius) / 2);
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pango_matrix_scale (&matrix, device_radius / RADIUS, device_radius / RADIUS);
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/* Create a PangoLayout, set the font and text */
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context = gtk_widget_create_pango_context (widget);
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layout = pango_layout_new (context);
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pango_layout_set_text (layout, "Text", -1);
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desc = pango_font_description_from_string (FONT);
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pango_layout_set_font_description (layout, desc);
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pango_font_description_free (desc);
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/* Draw the layout N_WORDS times in a circle */
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for (i = 0; i < N_WORDS; i++)
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{
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GdkColor color;
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PangoMatrix rotated_matrix = matrix;
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int width, height;
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double angle = (360. * i) / N_WORDS;
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/* Gradient from red at angle == 60 to blue at angle == 300 */
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color.red = 65535 * (1 + cos ((angle - 60) * M_PI / 180.)) / 2;
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color.green = 0;
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color.blue = 65535 - color.red;
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gdk_pango_renderer_set_override_color (GDK_PANGO_RENDERER (renderer),
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PANGO_RENDER_PART_FOREGROUND, &color);
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pango_matrix_rotate (&rotated_matrix, angle);
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pango_context_set_matrix (context, &rotated_matrix);
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/* Inform Pango to re-layout the text with the new transformation matrix */
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pango_layout_context_changed (layout);
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pango_layout_get_size (layout, &width, &height);
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pango_renderer_draw_layout (renderer, layout,
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- width / 2, - RADIUS * PANGO_SCALE);
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}
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/* Clean up default renderer, since it is shared */
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gdk_pango_renderer_set_override_color (GDK_PANGO_RENDERER (renderer),
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PANGO_RENDER_PART_FOREGROUND, NULL);
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gdk_pango_renderer_set_drawable (GDK_PANGO_RENDERER (renderer), NULL);
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gdk_pango_renderer_set_gc (GDK_PANGO_RENDERER (renderer), NULL);
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/* free the objects we created */
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g_object_unref (layout);
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g_object_unref (context);
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return FALSE;
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}
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GtkWidget *
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do_rotated_text (GtkWidget *do_widget)
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{
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GtkWidget *drawing_area;
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if (!window)
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{
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const GdkColor white = { 0, 0xffff, 0xffff, 0xffff };
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window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
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gtk_window_set_screen (GTK_WINDOW (window),
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gtk_widget_get_screen (do_widget));
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gtk_window_set_title (GTK_WINDOW (window), "Rotated Text");
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g_signal_connect (window, "destroy", G_CALLBACK (gtk_widget_destroyed), &window);
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drawing_area = gtk_drawing_area_new ();
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gtk_container_add (GTK_CONTAINER (window), drawing_area);
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/* This overrides the background color from the theme */
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gtk_widget_modify_bg (drawing_area, GTK_STATE_NORMAL, &white);
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g_signal_connect (drawing_area, "expose-event",
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G_CALLBACK (rotated_text_expose_event), NULL);
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gtk_window_set_default_size (GTK_WINDOW (window), 2 * RADIUS, 2 * RADIUS);
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}
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if (!GTK_WIDGET_VISIBLE (window))
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{
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gtk_widget_show_all (window);
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}
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else
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{
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gtk_widget_destroy (window);
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window = NULL;
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}
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return window;
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}
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