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showimg-example.html@ 203

Last change on this file since 203 was 190, checked in by rudi, 14 years ago
reference documentation added
File size: 39.7 KB

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1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
2	<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/examples/showimg/showimg.doc:4 -->
3	<html>
4	<head>
5	<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
6	<title>Show Image</title>
7	<style type="text/css"><!--
8	fn { margin-left: 1cm; text-indent: -1cm; }
9	a:link { color: #004faf; text-decoration: none }
10	a:visited { color: #672967; text-decoration: none }
11	body { background: #ffffff; color: black; }
12	--></style>
13	</head>
14	<body>
15
16	<table border="0" cellpadding="0" cellspacing="0" width="100%">
17	<tr bgcolor="#E5E5E5">
18	<td valign=center>
19	<a href="index.html">
20	<font color="#004faf">Home</font></a>
21	\| <a href="classes.html">
22	<font color="#004faf">All Classes</font></a>
23	\| <a href="mainclasses.html">
24	<font color="#004faf">Main Classes</font></a>
25	\| <a href="annotated.html">
26	<font color="#004faf">Annotated</font></a>
27	\| <a href="groups.html">
28	<font color="#004faf">Grouped Classes</font></a>
29	\| <a href="functions.html">
30	<font color="#004faf">Functions</font></a>
31	</td>
32	<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>Show Image</h1>
33
34
35	<p>
36	This example reads and displays an image in any supported image
37	format (GIF, BMP, PPM, XMP, etc.).
38	<p> <hr>
39	<p> Header file:
40	<p> <pre>/****************************************************************************
41	** $Id: showimg-example.html 2051 2007-02-21 10:04:20Z chehrlic $
42	**
43	** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
44	**
45	** This file is part of an example program for Qt. This example
46	** program may be used, distributed and modified without limitation.
47	**
48	*****************************************************************************/
49
50	#ifndef SHOWIMG_H
51	#define SHOWIMG_H
52
53	#include <<a href="qwidget-h.html">qwidget.h</a>>
54	#include <<a href="qimage-h.html">qimage.h</a>>
55
56
57	class QLabel;
58	class QMenuBar;
59	class QPopupMenu;
60
61	class ImageViewer : public <a href="qwidget.html">QWidget</a>
62	{
63	<a href="metaobjects.html#Q_OBJECT">Q_OBJECT</a>
64	public:
65	ImageViewer( <a href="qwidget.html">QWidget</a> parent=0, const char name=0, int wFlags=0 );
66	~ImageViewer();
67	bool loadImage( const <a href="qstring.html">QString</a>& );
68	protected:
69	void paintEvent( <a href="qpaintevent.html">QPaintEvent</a> * );
70	void resizeEvent( <a href="qresizeevent.html">QResizeEvent</a> * );
71	void mousePressEvent( <a href="qmouseevent.html">QMouseEvent</a> * );
72	void mouseReleaseEvent( <a href="qmouseevent.html">QMouseEvent</a> * );
73	void mouseMoveEvent( <a href="qmouseevent.html">QMouseEvent</a> * );
74
75	private:
76	void scale();
77	int conversion_flags;
78	bool smooth() const;
79	bool useColorContext() const;
80	int alloc_context;
81	bool convertEvent( <a href="qmouseevent.html">QMouseEvent</a>* e, int& x, int& y );
82	<a href="qstring.html">QString</a> filename;
83	<a href="qimage.html">QImage</a> image; // the loaded image
84	<a href="qpixmap.html">QPixmap</a> pm; // the converted pixmap
85	<a href="qpixmap.html">QPixmap</a> pmScaled; // the scaled pixmap
86
87	<a href="qmenubar.html">QMenuBar</a> *menubar;
88	<a href="qpopupmenu.html">QPopupMenu</a> *file;
89	<a href="qpopupmenu.html">QPopupMenu</a> *saveimage;
90	<a href="qpopupmenu.html">QPopupMenu</a> *savepixmap;
91	<a href="qpopupmenu.html">QPopupMenu</a> *edit;
92	<a href="qpopupmenu.html">QPopupMenu</a> *options;
93
94	<a href="qwidget.html">QWidget</a> *helpmsg;
95	<a href="qlabel.html">QLabel</a> *status;
96	int si, sp, ac, co, mo, fd, bd, // Menu item ids
97	td, ta, ba, fa, au, ad, dd,
98	ss, cc, t1, t8, t32;
99	void updateStatus();
100	void setMenuItemFlags();
101	bool reconvertImage();
102	int pickx, picky;
103	int clickx, clicky;
104	bool may_be_other;
105	static ImageViewer* other;
106	void setImage(const <a href="qimage.html">QImage</a>& newimage);
107
108	private slots:
109	void to1Bit();
110	void to8Bit();
111	void to32Bit();
112	void toBitDepth(int);
113
114	void copy();
115	void paste();
116
117	void hFlip();
118	void vFlip();
119	void rot180();
120
121	void editText();
122
123	void newWindow();
124	void openFile();
125	void saveImage(int);
126	void savePixmap(int);
127	void giveHelp();
128	void doOption(int);
129	void copyFrom(ImageViewer*);
130	};
131
132
133	#endif // SHOWIMG_H
134	</pre>
135
136	<p> <hr>
137	<p> Implementation:
138	<p> <pre>/****************************************************************************
139	** $Id: showimg-example.html 2051 2007-02-21 10:04:20Z chehrlic $
140	**
141	** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
142	**
143	** This file is part of an example program for Qt. This example
144	** program may be used, distributed and modified without limitation.
145	**
146	*****************************************************************************/
147
148	#include "showimg.h"
149	#include "imagetexteditor.h"
150	#include <<a href="qmenubar-h.html">qmenubar.h</a>>
151	#include <<a href="qfiledialog-h.html">qfiledialog.h</a>>
152	#include <<a href="qmessagebox-h.html">qmessagebox.h</a>>
153	#include <<a href="qpopupmenu-h.html">qpopupmenu.h</a>>
154	#include <<a href="qlabel-h.html">qlabel.h</a>>
155	#include <<a href="qpainter-h.html">qpainter.h</a>>
156	#include <<a href="qapplication-h.html">qapplication.h</a>>
157	#include <<a href="qclipboard-h.html">qclipboard.h</a>>
158
159
160	/*
161	In the constructor, we just pass the standard parameters on to
162	QWidget.
163
164	The menu uses a single slot to simplify the process of adding
165	more items to the options menu.
166	*/
167	<a name="f405"></a>ImageViewer::ImageViewer( <a href="qwidget.html">QWidget</a> parent, const char name, int wFlags )
168	: <a href="qwidget.html">QWidget</a>( parent, name, wFlags ),
169	conversion_flags( PreferDither ),
170	helpmsg( 0 )
171	{
172	pickx = -1;
173	picky = -1;
174	clickx = -1;
175	clicky = -1;
176	alloc_context = 0;
177
178	menubar = new <a href="qmenubar.html">QMenuBar</a>(this);
179	<a name="x1326"></a> menubar-><a href="qmenubar.html#setSeparator">setSeparator</a>( QMenuBar::InWindowsStyle );
180
181	<a name="x1323"></a> <a href="qstrlist.html">QStrList</a> fmt = QImage::<a href="qimage.html#outputFormats">outputFormats</a>();
182	saveimage = new <a href="qpopupmenu.html">QPopupMenu</a>( menubar );
183	savepixmap = new <a href="qpopupmenu.html">QPopupMenu</a>( menubar );
184	<a name="x1344"></a><a name="x1343"></a> for (const char* f = fmt.<a href="qptrlist.html#first">first</a>(); f; f = fmt.<a href="qptrlist.html#next">next</a>()) {
185	<a name="x1327"></a> saveimage-><a href="qmenudata.html#insertItem">insertItem</a>( f );
186	savepixmap-><a href="qmenudata.html#insertItem">insertItem</a>( f );
187	}
188	<a name="x1341"></a> <a href="qobject.html#connect">connect</a>( saveimage, SIGNAL(<a href="qpopupmenu.html#activated">activated</a>(int)), this, SLOT(saveImage(int)) );
189	<a href="qobject.html#connect">connect</a>( savepixmap, SIGNAL(<a href="qpopupmenu.html#activated">activated</a>(int)), this, SLOT(savePixmap(int)) );
190
191	file = new <a href="qpopupmenu.html">QPopupMenu</a>( menubar );
192	menubar-><a href="qmenudata.html#insertItem">insertItem</a>( "&File", file );
193	file-><a href="qmenudata.html#insertItem">insertItem</a>( "&New window", this, SLOT(newWindow()), CTRL+Key_N );
194	file-><a href="qmenudata.html#insertItem">insertItem</a>( "&Open...", this, SLOT(openFile()), CTRL+Key_O );
195	si = file-><a href="qmenudata.html#insertItem">insertItem</a>( "Save image", saveimage );
196	sp = file-><a href="qmenudata.html#insertItem">insertItem</a>( "Save pixmap", savepixmap );
197	<a name="x1328"></a> file-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
198	file-><a href="qmenudata.html#insertItem">insertItem</a>( "E&xit", qApp, SLOT(<a href="qapplication.html#quit">quit</a>()), CTRL+Key_Q );
199
200	edit = new <a href="qpopupmenu.html">QPopupMenu</a>( menubar );
201	menubar-><a href="qmenudata.html#insertItem">insertItem</a>( "&Edit", edit );
202	edit-><a href="qmenudata.html#insertItem">insertItem</a>("&Copy", this, SLOT(copy()), CTRL+Key_C);
203	edit-><a href="qmenudata.html#insertItem">insertItem</a>("&Paste", this, SLOT(paste()), CTRL+Key_V);
204	edit-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
205	edit-><a href="qmenudata.html#insertItem">insertItem</a>("&Horizontal flip", this, SLOT(hFlip()), ALT+Key_H);
206	edit-><a href="qmenudata.html#insertItem">insertItem</a>("&Vertical flip", this, SLOT(vFlip()), ALT+Key_V);
207	edit-><a href="qmenudata.html#insertItem">insertItem</a>("&Rotate 180", this, SLOT(rot180()), ALT+Key_R);
208	edit-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
209	edit-><a href="qmenudata.html#insertItem">insertItem</a>("&Text...", this, SLOT(editText()));
210	edit-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
211	t1 = edit-><a href="qmenudata.html#insertItem">insertItem</a>( "Convert to &1 bit", this, SLOT(to1Bit()) );
212	t8 = edit-><a href="qmenudata.html#insertItem">insertItem</a>( "Convert to &8 bit", this, SLOT(to8Bit()) );
213	t32 = edit-><a href="qmenudata.html#insertItem">insertItem</a>( "Convert to &32 bit", this, SLOT(to32Bit()) );
214
215	options = new <a href="qpopupmenu.html">QPopupMenu</a>( menubar );
216	menubar-><a href="qmenudata.html#insertItem">insertItem</a>( "&Options", options );
217	ac = options-><a href="qmenudata.html#insertItem">insertItem</a>( "AutoColor" );
218	co = options-><a href="qmenudata.html#insertItem">insertItem</a>( "ColorOnly" );
219	mo = options-><a href="qmenudata.html#insertItem">insertItem</a>( "MonoOnly" );
220	options-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
221	fd = options-><a href="qmenudata.html#insertItem">insertItem</a>( "DiffuseDither" );
222	bd = options-><a href="qmenudata.html#insertItem">insertItem</a>( "OrderedDither" );
223	td = options-><a href="qmenudata.html#insertItem">insertItem</a>( "ThresholdDither" );
224	options-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
225	ta = options-><a href="qmenudata.html#insertItem">insertItem</a>( "ThresholdAlphaDither" );
226	ba = options-><a href="qmenudata.html#insertItem">insertItem</a>( "OrderedAlphaDither" );
227	fa = options-><a href="qmenudata.html#insertItem">insertItem</a>( "DiffuseAlphaDither" );
228	options-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
229	ad = options-><a href="qmenudata.html#insertItem">insertItem</a>( "PreferDither" );
230	dd = options-><a href="qmenudata.html#insertItem">insertItem</a>( "AvoidDither" );
231	options-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
232	ss = options-><a href="qmenudata.html#insertItem">insertItem</a>( "Smooth scaling" );
233	cc = options-><a href="qmenudata.html#insertItem">insertItem</a>( "Use color context" );
234	<a name="x1309"></a> if ( QApplication::<a href="qapplication.html#colorSpec">colorSpec</a>() == QApplication::ManyColor )
235	<a name="x1331"></a> options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( cc, FALSE );
236	<a name="x1342"></a> options-><a href="qpopupmenu.html#setCheckable">setCheckable</a>( TRUE );
237	setMenuItemFlags();
238
239	menubar-><a href="qmenudata.html#insertSeparator">insertSeparator</a>();
240
241	<a href="qpopupmenu.html">QPopupMenu</a>* help = new <a href="qpopupmenu.html">QPopupMenu</a>( menubar );
242	menubar-><a href="qmenudata.html#insertItem">insertItem</a>( "&Help", help );
243	help-><a href="qmenudata.html#insertItem">insertItem</a>( "Help!", this, SLOT(giveHelp()), CTRL+Key_H );
244
245	<a href="qobject.html#connect">connect</a>( options, SIGNAL(<a href="qpopupmenu.html#activated">activated</a>(int)), this, SLOT(doOption(int)) );
246
247	status = new <a href="qlabel.html">QLabel</a>(this);
248	status-><a href="qframe.html#setFrameStyle">setFrameStyle</a>( QFrame::WinPanel \| QFrame::Sunken );
249	<a name="x1354"></a> status-><a href="qwidget.html#setFixedHeight">setFixedHeight</a>( <a href="qwidget.html#fontMetrics">fontMetrics</a>().height() + 4 );
250
251	<a href="qwidget.html#setMouseTracking">setMouseTracking</a>( TRUE );
252	}
253
254	ImageViewer::~ImageViewer()
255	{
256	if ( alloc_context )
257	<a name="x1313"></a> QColor::<a href="qcolor.html#destroyAllocContext">destroyAllocContext</a>( alloc_context );
258	if ( other == this )
259	other = 0;
260	}
261
262	/*
263	This function modifies the conversion_flags when an options menu item
264	is selected, then ensures all menu items are up to date, and reconverts
265	the image if possibly necessary.
266	*/
267	void <a name="f406"></a>ImageViewer::doOption(int item)
268	{
269	if ( item == ss \|\| item == cc ) {
270	// Toggle
271	<a name="x1329"></a> bool newbool = !options-><a href="qmenudata.html#isItemChecked">isItemChecked</a>(item);
272	<a name="x1330"></a> options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>(item, newbool);
273	// And reconvert...
274	reconvertImage();
275	<a href="qwidget.html#repaint">repaint</a>(image.hasAlphaBuffer()); // show image in widget
276	return;
277	}
278
279	if ( options-><a href="qmenudata.html#isItemChecked">isItemChecked</a>( item ) ) return; // They are all radio buttons
280
281	int ocf = conversion_flags;
282
283	if ( item == ac ) {
284	conversion_flags = ( conversion_flags & ~ColorMode_Mask ) \| AutoColor;
285	} else if ( item == co ) {
286	conversion_flags = ( conversion_flags & ~ColorMode_Mask ) \| ColorOnly;
287	} else if ( item == mo ) {
288	conversion_flags = ( conversion_flags & ~ColorMode_Mask ) \| MonoOnly;
289	} else if ( item == fd ) {
290	conversion_flags = ( conversion_flags & ~Dither_Mask ) \| DiffuseDither;
291	} else if ( item == bd ) {
292	conversion_flags = ( conversion_flags & ~Dither_Mask ) \| OrderedDither;
293	} else if ( item == td ) {
294	conversion_flags = ( conversion_flags & ~Dither_Mask ) \| ThresholdDither;
295	} else if ( item == ta ) {
296	conversion_flags = ( conversion_flags & ~AlphaDither_Mask ) \| ThresholdAlphaDither;
297	} else if ( item == fa ) {
298	conversion_flags = ( conversion_flags & ~AlphaDither_Mask ) \| DiffuseAlphaDither;
299	} else if ( item == ba ) {
300	conversion_flags = ( conversion_flags & ~AlphaDither_Mask ) \| OrderedAlphaDither;
301	} else if ( item == ad ) {
302	conversion_flags = ( conversion_flags & ~DitherMode_Mask ) \| PreferDither;
303	} else if ( item == dd ) {
304	conversion_flags = ( conversion_flags & ~DitherMode_Mask ) \| AvoidDither;
305	}
306
307	if ( ocf != conversion_flags ) {
308	setMenuItemFlags();
309	// And reconvert...
310	reconvertImage();
311	<a href="qwidget.html#repaint">repaint</a>(image.hasAlphaBuffer()); // show image in widget
312	}
313	}
314
315	/*
316	Set the options menu to reflect the conversion_flags value.
317	*/
318	void <a name="f407"></a>ImageViewer::setMenuItemFlags()
319	{
320	// File
321	bool valid_image = pm.size() != QSize( 0, 0 );
322	file-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( si, valid_image );
323	file-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( sp, valid_image );
324
325	// Edit
326	edit-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( t1, image.depth() != 1 );
327	edit-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( t8, image.depth() != 8 );
328	edit-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( t32, image.depth() != 32 );
329
330	// Options
331	bool may_need_color_dithering =
332	!valid_image
333	\|\| image.depth() == 32 && QPixmap::<a href="qpixmap.html#defaultDepth">defaultDepth</a>() < 24;
334	bool may_need_dithering = may_need_color_dithering
335	\|\| image.depth() > 1 && options-><a href="qmenudata.html#isItemChecked">isItemChecked</a>(mo)
336	\|\| image.depth() > 1 && QPixmap::<a href="qpixmap.html#defaultDepth">defaultDepth</a>() == 1;
337	bool has_alpha_mask = !valid_image \|\| image.hasAlphaBuffer();
338
339	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( fd, may_need_dithering );
340	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( bd, may_need_dithering );
341	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( td, may_need_dithering );
342
343	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( ta, has_alpha_mask );
344	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( fa, has_alpha_mask );
345	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( ba, has_alpha_mask );
346
347	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( ad, may_need_color_dithering );
348	options-><a href="qmenudata.html#setItemEnabled">setItemEnabled</a>( dd, may_need_color_dithering );
349
350	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( ac, (conversion_flags & ColorMode_Mask) == AutoColor );
351	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( co, (conversion_flags & ColorMode_Mask) == ColorOnly );
352	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( mo, (conversion_flags & ColorMode_Mask) == MonoOnly );
353	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( fd, (conversion_flags & Dither_Mask) == DiffuseDither );
354	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( bd, (conversion_flags & Dither_Mask) == OrderedDither );
355	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( td, (conversion_flags & Dither_Mask) == ThresholdDither );
356	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( ta, (conversion_flags & AlphaDither_Mask) == ThresholdAlphaDither );
357	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( fa, (conversion_flags & AlphaDither_Mask) == DiffuseAlphaDither );
358	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( ba, (conversion_flags & AlphaDither_Mask) == OrderedAlphaDither );
359	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( ad, (conversion_flags & DitherMode_Mask) == PreferDither );
360	options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( dd, (conversion_flags & DitherMode_Mask) == AvoidDither );
361	}
362
363	void <a name="f408"></a>ImageViewer::updateStatus()
364	{
365	if ( pm.size() == QSize( 0, 0 ) ) {
366	if ( !filename.isEmpty() )
367	status-><a href="qlabel.html#setText">setText</a>("Could not load image");
368	else
369	status-><a href="qlabel.html#setText">setText</a>("No image - select Open from File menu.");
370	} else {
371	<a href="qstring.html">QString</a> message, moremsg;
372	message.<a href="qstring.html#sprintf">sprintf</a>("%dx%d", image.width(), image.height());
373	if ( pm.size() != pmScaled.size() ) {
374	moremsg.sprintf(" [%dx%d]", pmScaled.width(),
375	pmScaled.height());
376	message += moremsg;
377	}
378	moremsg.sprintf(", %d bits ", image.depth());
379	message += moremsg;
380	if (image.valid(pickx,picky)) {
381	moremsg.sprintf("(%d,%d)=#%0*x ",
382	pickx, picky,
383	image.hasAlphaBuffer() ? 8 : 6,
384	image.pixel(pickx,picky));
385	message += moremsg;
386	}
387	if ( image.numColors() > 0 ) {
388	if (image.valid(pickx,picky)) {
389	moremsg.sprintf(", %d/%d colors", image.pixelIndex(pickx,picky),
390	image.numColors());
391	} else {
392	moremsg.sprintf(", %d colors", image.numColors());
393	}
394	message += moremsg;
395	}
396	if ( image.hasAlphaBuffer() ) {
397	if ( image.depth() == 8 ) {
398	int i;
399	bool alpha[256];
400	int nalpha=0;
401
402	for (i=0; i<256; i++)
403	alpha[i] = FALSE;
404
405	for (i=0; i<image.numColors(); i++) {
406	int alevel = image.color(i) >> 24;
407	if (!alpha[alevel]) {
408	alpha[alevel] = TRUE;
409	nalpha++;
410	}
411	}
412	moremsg.sprintf(", %d alpha levels", nalpha);
413	} else {
414	// Too many pixels to bother counting.
415	moremsg = ", 8-bit alpha channel";
416	}
417	message += moremsg;
418	}
419	status-><a href="qlabel.html#setText">setText</a>(message);
420	}
421	}
422
423	/*
424	This function saves the image.
425	*/
426	void <a name="f409"></a>ImageViewer::saveImage( int item )
427	{
428	<a name="x1332"></a> const char* fmt = saveimage-><a href="qmenudata.html#text">text</a>(item);
429	<a name="x1319"></a> <a href="qstring.html">QString</a> savefilename = QFileDialog::<a href="qfiledialog.html#getSaveFileName">getSaveFileName</a>(QString::null, <a href="qstring.html#QString-null">QString::null</a>,
430	this, filename);
431	if ( !savefilename.<a href="qstring.html#isEmpty">isEmpty</a>() )
432	if ( !image.save( savefilename, fmt ) )
433	<a name="x1333"></a> QMessageBox::<a href="qmessagebox.html#warning">warning</a>( this, "Save failed", "Error saving file" );
434	}
435
436	/*
437	This function saves the converted image.
438	*/
439	void <a name="f410"></a>ImageViewer::savePixmap( int item )
440	{
441	const char* fmt = savepixmap-><a href="qmenudata.html#text">text</a>(item);
442	<a href="qstring.html">QString</a> savefilename = QFileDialog::<a href="qfiledialog.html#getSaveFileName">getSaveFileName</a>(QString::null,
443	QString::null, this, filename);
444	if ( !savefilename.<a href="qstring.html#isEmpty">isEmpty</a>() )
445	if ( !pmScaled.save( savefilename, fmt ) )
446	QMessageBox::<a href="qmessagebox.html#warning">warning</a>( this, "Save failed", "Error saving file" );
447	}
448
449
450	void <a name="f411"></a>ImageViewer::newWindow()
451	{
452	ImageViewer* that = new ImageViewer(0, "new window", WDestructiveClose);
453	that->options-><a href="qmenudata.html#setItemChecked">setItemChecked</a>( that->cc, useColorContext() );
454	that-><a href="qwidget.html#show">show</a>();
455	}
456
457	/*
458	This function is the slot for processing the Open menu item.
459	*/
460	void <a name="f412"></a>ImageViewer::openFile()
461	{
462	<a name="x1318"></a> <a href="qstring.html">QString</a> newfilename = QFileDialog::<a href="qfiledialog.html#getOpenFileName">getOpenFileName</a>( QString::null,
463	QString::null,
464	this );
465	if ( !newfilename.<a href="qstring.html#isEmpty">isEmpty</a>() ) {
466	loadImage( newfilename ) ;
467	<a href="qwidget.html#repaint">repaint</a>(); // show image in widget
468	}
469	}
470
471	/*
472	This function loads an image from a file and resizes the widget to
473	exactly fit the image size. If the file was not found or the image
474	format was unknown it will resize the widget to fit the errorText
475	message (see above) displayed in the current font.
476
477	Returns TRUE if the image was successfully loaded.
478	*/
479
480	bool <a name="f413"></a>ImageViewer::loadImage( const <a href="qstring.html">QString</a>& fileName )
481	{
482	filename = fileName;
483	bool ok = FALSE;
484	if ( !filename.isEmpty() ) {
485	<a name="x1312"></a> QApplication::<a href="qapplication.html#setOverrideCursor">setOverrideCursor</a>( waitCursor ); // this might take time
486	ok = image.load(filename, 0);
487	pickx = -1;
488	clickx = -1;
489	if ( ok )
490	ok = reconvertImage();
491	if ( ok ) {
492	<a href="qwidget.html#setCaption">setCaption</a>( filename ); // set window caption
493	int w = pm.width();
494	int h = pm.height();
495
496	const int reasonable_width = 128;
497	if ( w < reasonable_width ) {
498	// Integer scale up to something reasonable
499	int multiply = ( reasonable_width + w - 1 ) / w;
500	w *= multiply;
501	h *= multiply;
502	}
503
504	<a name="x1347"></a><a name="x1325"></a> h += menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>(w) + status-><a href="qwidget.html#height">height</a>();
505	<a href="qwidget.html#resize">resize</a>( w, h ); // we resize to fit image
506	} else {
507	pm.resize(0,0); // couldn't load image
508	<a href="qwidget.html#update">update</a>();
509	}
510	<a name="x1311"></a> QApplication::<a href="qapplication.html#restoreOverrideCursor">restoreOverrideCursor</a>(); // restore original cursor
511	}
512	updateStatus();
513	setMenuItemFlags();
514	return ok;
515	}
516
517	bool <a name="f414"></a>ImageViewer::reconvertImage()
518	{
519	bool success = FALSE;
520
521	if ( image.isNull() ) return FALSE;
522
523	if ( alloc_context ) {
524	QColor::<a href="qcolor.html#destroyAllocContext">destroyAllocContext</a>( alloc_context );
525	alloc_context = 0;
526	}
527	if ( useColorContext() ) {
528	<a name="x1314"></a> alloc_context = QColor::<a href="qcolor.html#enterAllocContext">enterAllocContext</a>();
529	// Clear the image to hide flickering palette
530	<a href="qpainter.html">QPainter</a> painter(this);
531	<a name="x1338"></a> painter.<a href="qpainter.html#eraseRect">eraseRect</a>(0, menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>( <a href="qwidget.html#width">width</a>() ), width(), height());
532	}
533
534	QApplication::<a href="qapplication.html#setOverrideCursor">setOverrideCursor</a>( waitCursor ); // this might take time
535	if ( pm.convertFromImage(image, conversion_flags) )
536	{
537	pmScaled = QPixmap();
538	scale();
539	<a href="qwidget.html#resize">resize</a>( <a href="qwidget.html#width">width</a>(), height() );
540	success = TRUE; // load successful
541	} else {
542	pm.resize(0,0); // couldn't load image
543	}
544	updateStatus();
545	setMenuItemFlags();
546	QApplication::<a href="qapplication.html#restoreOverrideCursor">restoreOverrideCursor</a>(); // restore original cursor
547
548	if ( useColorContext() )
549	<a name="x1315"></a> QColor::<a href="qcolor.html#leaveAllocContext">leaveAllocContext</a>();
550
551	return success; // TRUE if loaded OK
552	}
553
554	bool <a name="f415"></a>ImageViewer::smooth() const
555	{
556	return options-><a href="qmenudata.html#isItemChecked">isItemChecked</a>(ss);
557	}
558
559	bool <a name="f416"></a>ImageViewer::useColorContext() const
560	{
561	return options-><a href="qmenudata.html#isItemChecked">isItemChecked</a>(cc);
562	}
563
564	/*
565	This functions scales the pixmap in the member variable "pm" to fit the
566	widget size and puts the resulting pixmap in the member variable "pmScaled".
567	*/
568
569	void <a name="f417"></a>ImageViewer::scale()
570	{
571	int h = <a href="qwidget.html#height">height</a>() - menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>( <a href="qwidget.html#width">width</a>() ) - status-><a href="qwidget.html#height">height</a>();
572
573	if ( image.isNull() ) return;
574
575	QApplication::<a href="qapplication.html#setOverrideCursor">setOverrideCursor</a>( waitCursor ); // this might take time
576	if ( <a href="qwidget.html#width">width</a>() == pm.width() && h == pm.height() )
577	{ // no need to scale if widget
578	pmScaled = pm; // size equals pixmap size
579	} else {
580	if (smooth()) {
581	pmScaled.convertFromImage(image.smoothScale(<a href="qwidget.html#width">width</a>(), h),
582	conversion_flags);
583	} else {
584	<a href="qwmatrix.html">QWMatrix</a> m; // <a href="qwmatrix.html#TransformationMode">transformation matrix</a>
585	<a name="x1357"></a> m.<a href="qwmatrix.html#scale">scale</a>(((double)<a href="qwidget.html#width">width</a>())/pm.width(),// define scale factors
586	((double)h)/pm.height());
587	pmScaled = pm.xForm( m ); // create scaled pixmap
588	}
589	}
590	QApplication::<a href="qapplication.html#restoreOverrideCursor">restoreOverrideCursor</a>(); // restore original cursor
591	}
592
593	/*
594	The resize event handler, if a valid pixmap was loaded it will call
595	scale() to fit the pixmap to the new widget size.
596	*/
597
598	<a name="x1353"></a>void ImageViewer::<a href="qwidget.html#resizeEvent">resizeEvent</a>( <a href="qresizeevent.html">QResizeEvent</a> * )
599	{
600	<a name="x1355"></a> status-><a href="qwidget.html#setGeometry">setGeometry</a>(0, height() - status-><a href="qwidget.html#height">height</a>(),
601	<a href="qwidget.html#width">width</a>(), status-><a href="qwidget.html#height">height</a>());
602
603	if ( pm.size() == QSize( 0, 0 ) ) // we couldn't load the image
604	return;
605
606	int h = <a href="qwidget.html#height">height</a>() - menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>( <a href="qwidget.html#width">width</a>() ) - status-><a href="qwidget.html#height">height</a>();
607	if ( <a href="qwidget.html#width">width</a>() != pmScaled.width() \|\| h != pmScaled.height())
608	{ // if new size,
609	scale(); // scale pmScaled to window
610	updateStatus();
611	}
612	if ( image.hasAlphaBuffer() )
613	<a href="qwidget.html#erase">erase</a>();
614	}
615
616	bool <a name="f418"></a>ImageViewer::convertEvent( <a href="qmouseevent.html">QMouseEvent</a>* e, int& x, int& y)
617	{
618	if ( pm.size() != QSize( 0, 0 ) ) {
619	int h = <a href="qwidget.html#height">height</a>() - menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>( <a href="qwidget.html#width">width</a>() ) - status-><a href="qwidget.html#height">height</a>();
620	<a name="x1335"></a> int nx = e-><a href="qmouseevent.html#x">x</a>() * image.width() / width();
621	<a name="x1336"></a> int ny = (e-><a href="qmouseevent.html#y">y</a>()-menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>( <a href="qwidget.html#width">width</a>() )) * image.height() / h;
622	if (nx != x \|\| ny != y ) {
623	x = nx;
624	y = ny;
625	updateStatus();
626	return TRUE;
627	}
628	}
629	return FALSE;
630	}
631
632	void ImageViewer::<a href="qwidget.html#mousePressEvent">mousePressEvent</a>( <a href="qmouseevent.html">QMouseEvent</a> *e )
633	{
634	may_be_other = convertEvent(e, clickx, clicky);
635	}
636
637	<a name="x1350"></a>void ImageViewer::<a href="qwidget.html#mouseReleaseEvent">mouseReleaseEvent</a>( <a href="qmouseevent.html">QMouseEvent</a> * )
638	{
639	if ( may_be_other )
640	other = this;
641	}
642
643	/*
644	Record the pixel position of interest.
645	*/
646	void ImageViewer::<a href="qwidget.html#mouseMoveEvent">mouseMoveEvent</a>( <a href="qmouseevent.html">QMouseEvent</a> *e )
647	{
648	if (convertEvent(e,pickx,picky)) {
649	updateStatus();
650	<a name="x1334"></a> if ((e-><a href="qmouseevent.html#state">state</a>()&LeftButton)) {
651	may_be_other = FALSE;
652	if ( clickx >= 0 && other) {
653	copyFrom(other);
654	}
655	}
656	}
657	}
658
659	/*
660	Draws the portion of the scaled pixmap that needs to be updated or prints
661	an error message if no legal pixmap has been loaded.
662	*/
663
664	void ImageViewer::<a href="qwidget.html#paintEvent">paintEvent</a>( <a href="qpaintevent.html">QPaintEvent</a> *e )
665	{
666	if ( pm.size() != QSize( 0, 0 ) ) { // is an image loaded?
667	<a href="qpainter.html">QPainter</a> painter(this);
668	<a name="x1340"></a><a name="x1339"></a> painter.<a href="qpainter.html#setClipRect">setClipRect</a>(e-><a href="qpaintevent.html#rect">rect</a>());
669	<a name="x1337"></a> painter.<a href="qpainter.html#drawPixmap">drawPixmap</a>(0, menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>( <a href="qwidget.html#width">width</a>() ), pmScaled);
670	}
671	}
672
673
674	/*
675	Explain anything that might be confusing.
676	*/
677	void <a name="f419"></a>ImageViewer::giveHelp()
678	{
679	if (!helpmsg) {
680	<a href="qstring.html">QString</a> helptext =
681	"<b>Usage:</b> <tt>showimg [-m] <i>filename ...</i></tt>"
682	"<blockquote>"
683	"<tt>-m</tt> - use <i>ManyColor</i> color spec"
684	"</blockquote>"
685	"<p>Supported input formats:"
686	"<blockquote>";
687	<a name="x1321"></a> helptext += QImage::<a href="qimage.html#inputFormatList">inputFormatList</a>().join(", ");
688	helptext += "</blockquote>";
689
690	helpmsg = new <a href="qmessagebox.html">QMessageBox</a>( "Help", helptext,
691	QMessageBox::Information, QMessageBox::Ok, 0, 0, 0, 0, FALSE );
692	}
693	<a name="x1317"></a> helpmsg-><a href="qdialog.html#show">show</a>();
694	<a name="x1352"></a> helpmsg-><a href="qwidget.html#raise">raise</a>();
695	}
696
697	void <a name="f420"></a>ImageViewer::copyFrom(ImageViewer* s)
698	{
699	if ( clickx >= 0 ) {
700	int dx = clickx;
701	int dy = clicky;
702	int sx = s->clickx;
703	int sy = s->clicky;
704	int sw = QABS(clickx - pickx)+1;
705	int sh = QABS(clicky - picky)+1;
706	if ( clickx > pickx ) {
707	dx = pickx;
708	sx -= sw-1;
709	}
710	if ( clicky > picky ) {
711	dy = picky;
712	sy -= sh-1;
713	}
714	<a href="qimage.html#bitBlt">bitBlt</a>( &image, dx, dy, &s->image, sx, sy, sw, sh );
715	reconvertImage();
716	<a href="qwidget.html#repaint">repaint</a>( image.hasAlphaBuffer() );
717	}
718	}
719	ImageViewer* ImageViewer::other = 0;
720
721	void <a name="f421"></a>ImageViewer::hFlip()
722	{
723	setImage(image.mirror(TRUE,FALSE));
724	}
725
726	void <a name="f422"></a>ImageViewer::vFlip()
727	{
728	setImage(image.mirror(FALSE,TRUE));
729	}
730
731	void <a name="f423"></a>ImageViewer::rot180()
732	{
733	setImage(image.mirror(TRUE,TRUE));
734	}
735
736	void <a name="f424"></a>ImageViewer::copy()
737	{
738	#ifndef QT_NO_MIMECLIPBOARD
739	<a name="x1308"></a> QApplication::<a href="qapplication.html#clipboard">clipboard</a>()->setImage(image); // Less information loss
740	#endif
741	}
742
743	void <a name="f425"></a>ImageViewer::paste()
744	{
745	#ifndef QT_NO_MIMECLIPBOARD
746	<a href="qimage.html">QImage</a> p = QApplication::<a href="qapplication.html#clipboard">clipboard</a>()->image();
747	<a name="x1322"></a> if ( !p.<a href="qimage.html#isNull">isNull</a>() ) {
748	filename = "pasted";
749	setImage(p);
750	}
751	#endif
752	}
753
754	void <a name="f426"></a>ImageViewer::setImage(const <a href="qimage.html">QImage</a>& newimage)
755	{
756	image = newimage;
757
758	pickx = -1;
759	clickx = -1;
760	<a href="qwidget.html#setCaption">setCaption</a>( filename ); // set window caption
761	int w = image.width();
762	int h = image.height();
763	if ( !w )
764	return;
765
766	const int reasonable_width = 128;
767	if ( w < reasonable_width ) {
768	// Integer scale up to something reasonable
769	int multiply = ( reasonable_width + w - 1 ) / w;
770	w *= multiply;
771	h *= multiply;
772	}
773
774	h += menubar-><a href="qmenubar.html#heightForWidth">heightForWidth</a>(w) + status-><a href="qwidget.html#height">height</a>();
775	<a href="qwidget.html#resize">resize</a>( w, h ); // we resize to fit image
776
777	reconvertImage();
778	<a href="qwidget.html#repaint">repaint</a>( image.hasAlphaBuffer() );
779
780	updateStatus();
781	setMenuItemFlags();
782	}
783
784	void <a name="f427"></a>ImageViewer::editText()
785	{
786	ImageTextEditor editor(image,this);
787	editor.<a href="qdialog.html#exec">exec</a>();
788	}
789
790	void <a name="f428"></a>ImageViewer::to1Bit()
791	{
792	toBitDepth(1);
793	}
794
795	void <a name="f429"></a>ImageViewer::to8Bit()
796	{
797	toBitDepth(8);
798	}
799
800	void <a name="f430"></a>ImageViewer::to32Bit()
801	{
802	toBitDepth(32);
803	}
804
805	void <a name="f431"></a>ImageViewer::toBitDepth(int d)
806	{
807	image = image.convertDepth(d);
808	reconvertImage();
809	<a href="qwidget.html#repaint">repaint</a>( image.hasAlphaBuffer() );
810	}
811	</pre>
812
813	<p> <hr>
814	<p> Main:
815	<p> <pre>/****************************************************************************
816	** $Id: showimg-example.html 2051 2007-02-21 10:04:20Z chehrlic $
817	**
818	** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
819	**
820	** This file is part of an example program for Qt. This example
821	** program may be used, distributed and modified without limitation.
822	**
823	*****************************************************************************/
824
825	#include "showimg.h"
826	#include "imagefip.h"
827	#include <<a href="qapplication-h.html">qapplication.h</a>>
828	#include <<a href="qimage-h.html">qimage.h</a>>
829
830	int main( int argc, char **argv )
831	{
832	if ( argc > 1 && QString(argv[1]) == "-m" ) {
833	<a name="x1361"></a> QApplication::<a href="qapplication.html#setColorSpec">setColorSpec</a>( QApplication::ManyColor );
834	argc--;
835	argv++;
836	}
837	else if ( argc > 1 && QString(argv[1]) == "-n" ) {
838	QApplication::<a href="qapplication.html#setColorSpec">setColorSpec</a>( QApplication::NormalColor );
839	argc--;
840	argv++;
841	}
842	else {
843	QApplication::<a href="qapplication.html#setColorSpec">setColorSpec</a>( QApplication::CustomColor );
844	}
845
846	<a href="qapplication.html">QApplication</a> a( argc, argv );
847
848	ImageIconProvider iip;
849	<a name="x1362"></a> QFileDialog::<a href="qfiledialog.html#setIconProvider">setIconProvider</a>( &iip );
850
851	if ( argc <= 1 ) {
852	// Create a window which looks after its own existence.
853	ImageViewer *w =
854	new ImageViewer(0, "new window", Qt::WDestructiveClose \| Qt::WResizeNoErase );
855	<a name="x1364"></a> w-><a href="qwidget.html#setCaption">setCaption</a>("Qt Example - Image Viewer");
856	w-><a href="qwidget.html#show">show</a>();
857	} else {
858	for ( int i=1; i<argc; i++ ) {
859	// Create a window which looks after its own existence.
860	ImageViewer *w =
861	new ImageViewer(0, argv[i], Qt::WDestructiveClose \| Qt::WResizeNoErase );
862	w-><a href="qwidget.html#setCaption">setCaption</a>("Qt Example - Image Viewer");
863	w->loadImage( argv[i] );
864	w-><a href="qwidget.html#show">show</a>();
865	}
866	}
867
868	QObject::<a href="qobject.html#connect">connect</a>(qApp, SIGNAL(<a href="qapplication.html#lastWindowClosed">lastWindowClosed</a>()), qApp, SLOT(<a href="qapplication.html#quit">quit</a>()));
869
870	return a.<a href="qapplication.html#exec">exec</a>();
871	}
872	</pre>
873
874	<p>See also <a href="examples.html">Examples</a>.
875
876	<!-- eof -->
877	<p><address><hr><div align=center>
878	<table width=100% cellspacing=0 border=0><tr>
879	<td>Copyright © 2007
880	<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
881	<td align=right><div align=right>Qt 3.3.8</div>
882	</table></div></address></body>
883	</html>

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