Highlight a widget partially in GTK+ - gtk

I have a list box in part of my interface, and I want to highlight the GtkListBoxRows individually by progress. You load several files, and my program works on it each file individually, and I want to highlight the list box row like a progress bar. It is very similar to a progress bar, just the contents inside are buttons and some text. Is there a specific Cairo/Pango function that allows the recoloring?

I have a solution here using Gtkmm (should be easily translatable to C). I have a series of 5 buttons aligned horizontally inside a container and a "Make progress" button. When you click on it, child buttons in the container are updated to show the progress:
#include <iostream>
#include <gtkmm.h>
class MainWindow : public Gtk::ApplicationWindow
{
public:
MainWindow();
private:
Gtk::Grid m_container;
Gtk::Button m_progressButton;
int m_progressTracker = 0;
};
MainWindow::MainWindow()
: m_progressButton("Make progress...")
{
// Add five buttons to the container (horizontally):
for(int index = 0; index < 5; ++index)
{
Gtk::Button* button = Gtk::make_managed<Gtk::Button>("B" + std::to_string(index));
m_container.attach(*button, index, 0, 1, 1);
}
// Add a button to control progress:
m_container.attach(m_progressButton, 0, 1, 5, 1);
// Add handler to the progress button.
m_progressButton.signal_clicked().connect(
// Each time the button is clicked, the "hilighting" of the buttons
// in the container progresses until completed:
[this]()
{
Gtk::Widget* child = m_container.get_child_at(m_progressTracker, 0);
if(child != nullptr)
{
std::cout << "Making progress ..." << std::endl;
// Change the button's background color:
Glib::RefPtr<Gtk::CssProvider> cssProvider = Gtk::CssProvider::create();
cssProvider->load_from_data("button {background-image: image(cyan);}");
child->get_style_context()->add_provider(cssProvider, GTK_STYLE_PROVIDER_PRIORITY_USER);
// Update for next child...
++m_progressTracker;
}
}
);
// Make m_container a child of the window:
add(m_container);
}
int main(int argc, char *argv[])
{
std::cout << "Gtkmm version : " << gtk_get_major_version() << "."
<< gtk_get_minor_version() << "."
<< gtk_get_micro_version() << std::endl;
auto app = Gtk::Application::create(argc, argv, "org.gtkmm.examples.base");
MainWindow window;
window.show_all();
return app->run(window);
}
In your case, you will have to adapt the container and the signal (maybe you will need something else to trigger the redraw), but it should work pretty much the same as far as changing the background color is concerned. You can build this (using Gtkmm 3.24) with:
g++ main.cpp -o example.out `pkg-config --cflags --libs gtkmm-3.0`

Related

blank dialogue box without my text nor OK button

I'm trying to popup an OK message box in my gtk browser, but all I'm getting is blank grey square patch without my text in it and even button is not visible.
PFB the function which I'm using to render message box :
Void DisplayOKPopup()
{
dialogue=gtk_message_dialogue_new(GTK_WINDOW(WebtBrowserWindow),
GTK_DIALOGUE_DESTROY_WITH_PARENT,
GTK_MESSAGE_INFO,
GTK_BUTTONS_OK,
"text message");
gtk_widget_show(dialogue);
LOGDEBUG(" 1");
gtk_dialogue_run(GTK_DIALOGUE (dialogue));
LOGDEBUG("2");
gtk_widget_destroy (dialogue);
}
As per my debug log, I can see that control is passing till LOGDEBUG("1") and after that it goes to gtk_dialogue_run after that UI is getting crashed, the line next to run i.e LOGDEBUG("2") is not getting executed.
Kindly provide your inputs as I'm working on this since 3 days:!
As concluded, the problem arises from the use of threads. There are several approaches to solve the issue but since there is not code, I'll try with a simple example so that you can recreate it on your code.
Take a global Boolean variable as a flag and on your thread, set it to true so that a "periodic" idle callback can check it and if the flag is TRUE then show the dialog. The logic is that the Gtk UI functions are called from the mainloop/main thread and not from the worker threads.
DisplayOkPopup just has a simple "counter" from 0 to MAX_INT (32 bits) and set's the global flag as TRUE.
check_for_dialog it's a callback that runs on mainloop idle time and check for the flag, if TRUE then runs the dialog.
exit is dirty and will output errors but the goal ain't that, its just a tip/hint for your solution.
Example:
#include <gtk/gtk.h>
gboolean dialog_active;
gboolean show_dialog_popup;
GtkWidget *window;
gpointer DisplayOKPopup (gpointer user_data) {
int i;
while (TRUE) {
for (i = 0; i < G_MAXINT32; i++) {
// nop
}
show_dialog_popup = TRUE;
}
return NULL;
}
gboolean check_for_dialog (gpointer user_data) {
if (show_dialog_popup == TRUE && dialog_active == FALSE) {
dialog_active = TRUE;
GtkWidget *dialog = gtk_message_dialog_new(GTK_WINDOW(window),
GTK_DIALOG_DESTROY_WITH_PARENT,
GTK_MESSAGE_INFO,
GTK_BUTTONS_OK,
"text message");
gtk_dialog_run(GTK_DIALOG (dialog));
show_dialog_popup = FALSE;
dialog_active = FALSE;
gtk_widget_destroy(dialog);
}
return TRUE;
}
static void app_activate(GtkApplication *app, gpointer user_data) {
window = gtk_application_window_new(app);
gtk_window_set_title(GTK_WINDOW(window), "Window Title Here");
gtk_window_set_default_size(GTK_WINDOW(window), 700, 400);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
//gtk_container_add(GTK_CONTAINER(window), fixed);
gtk_widget_show_all(window);
g_idle_add(check_for_dialog, NULL);
g_thread_new("my thread", DisplayOKPopup, NULL);
}
int main(int argc, char **argv) {
GtkApplication *app;
int status;
show_dialog_popup = FALSE;
dialog_active = FALSE;
app = gtk_application_new("your.application.id", G_APPLICATION_FLAGS_NONE);
g_signal_connect(app, "activate", G_CALLBACK(app_activate), NULL);
status = g_application_run(G_APPLICATION(app), argc, argv);
g_object_unref(app);
return status;
}
Build and run:
$ gcc -o test test.c `pkg-config --cflags --libs gtk+-3.0`
$ ./test
Result:
EDIT:
Answer to your comment is:
To have custom buttons on your dialog then use:
gtk_dialog_new_with_buttons
gtk_dialog_add_button (if dialog exists, will add 1 button)
gtk_dialog_add_buttons (same as above but can add many buttons)
Example for 1):
dialog = gtk_dialog_new_with_buttons ("My dialog",
main_app_window,
flags,
"_OK",
GTK_RESPONSE_ACCEPT,
"_Cancel",
GTK_RESPONSE_REJECT,
NULL);
Example for 2):
gtk_dialog_add_button (GTK_DIALOG(dialog),
"This is my button",
GTK_RESPONSE_ACCEPT);
Example for 3) is same as 2) but can handle many buttons and terminates with NULL.

SDL2 issue undefined reference SDL_main

i,v downloaded SDL2 library on windows7 64bit i,m using MinGW compiler and my IDE is : eclipse Mars
so the problem is when i build my SDL program i face this problem :
C:\Users\{C}\Desktop\eclipse\MinGW\lib/libSDL2main.a(SDL_windows_main.o):SDL_windows_main.c:(.text+0x18): undefined reference toSDL_main'`
i did every thing correctly but i keep facing this issue and that,s the whole CDT build :
13:19:24 Incremental Build of configuration Debug for project
boring **** Info: Internal Builder is used for build g++
"-LC:\\Users\\{C}\\Desktop\\eclipse\\MinGW\\lib" -o boring.exe
"src\\boring.o" -lmingw32 -lSDL2main -lSDL2
C:\Users\{C}\Desktop\eclipse\MinGW\lib/libSDL2main.a(SDL_windows_main.o):SDL_windows_main.c:(.text+0x18):
undefined reference to `SDL_main' collect2.exe: error: ld returned 1
exit status 13:19:27 Build Finished (took 3s.337ms)
and here,s my source code:
#include <iostream>
#include <SDL2/SDL.h>
using namespace std;
int main() {
const int SCREEN_WIDTH = 800;
const int SCREEN_HEIGHT = 600;
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
cout << "SDL init failed." << endl;
return 1;
}
SDL_Window *window = SDL_CreateWindow("Particle Fire Explosion",
SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH SCREEN_HEIGHT, SDL_WINDOW_SHOWN);,
if (window == NULL) {
SDL_Quit();
return 2;
}
bool quit = false;
SDL_Event event;
while (!quit) {
// Update particles
// Draw particles
// Check for messages/events
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT) {
quit = true;
}
}
}
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
thanks;
SDL requires that you define your main exactly as main(int argc, char *argv[]). Please check if this resolves your problem.

goocanvas signal handling corrupted after using a dialog

I use a goocanvas and use signals for mouse events connected to some graphical items. If I use a dialog from a signal handler, all signals are broken after closing the dialog. Is this a bug of gtkmm/goocanvas or is this some kind of misuse in my program?
The wrong behavior is:
You can click somewhere in the canvas area, nothing is happen which is correct. If you click on the circle the signal handler starts the dialog which is also expected. After closing the dialog ( OK button ) you can click somewhere on the canvas and the signal handler is called which is wrong.
In my real program the signal handlers are sometimes never called and sometimes called on wrong areas and so on. A bit strange behavior. I hope someone can find the problem.
#include <gtkmm.h>
#include <goocanvasmm.h>
#include <sigc++/sigc++.h>
bool ShowDialog( const Glib::RefPtr<Goocanvas::Item>& item, GdkEventButton* ev)
{
enum { OK };
Gtk::Dialog dialog;
dialog.add_button( Gtk::Stock::OK, OK);
dialog.show_all_children();
dialog.run();
return false;
}
int main(int argc, char* argv[])
{
Gtk::Main app(&argc, &argv);
Goocanvas::init("example", "0.1", argc, argv);
Gtk::Window win;
Goocanvas::Canvas m_canvas;
m_canvas.set_size_request(640, 480);
m_canvas.set_bounds(0, 0, 800, 800);
Glib::RefPtr<Goocanvas::Item> root = m_canvas.get_root_item();
Glib::RefPtr<Goocanvas::Ellipse> outer = Goocanvas::Ellipse::create( 100,100,20,20);
outer->property_line_width() = 5;
outer->property_stroke_color() = "red";
outer->property_fill_color()="blue";
root->add_child( outer );
sigc::connection conn2= outer->signal_button_press_event().connect( sigc::ptr_fun(&ShowDialog));
win.add(m_canvas);
win.show_all_children();
Gtk::Main::run(win);
return 0;
}

using opencv features2d on iPhone

I'm trying to use feature detection via OpenCV on iOS and I'm running into a conundrum:
features2d relies on highgui
highgui can't be built on iOS (or at least not that I can figure out).
This leads me to believe: features2d just can't be used on iOS without rewriting the module to remove the calls to cvSaveImage() and cvLoadImage(). Is this wrong? Anyone run into this and solved it?
You are taking the wrong aproach, you dont need highgui since that library is only ment to make it easier for you to handle the results of your processing, you can simply do those steps manually.
for example, consider this HOG example:
#include <iostream>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
int
main(int argc, char *argv[])
{
const char *imagename = argc > 1 ? argv[1] : "../../image/pedestrian.png";
cv::Mat img = cv::imread(imagename, 1);
if(img.empty()) return -1;
cv::HOGDescriptor hog;
hog.setSVMDetector(cv::HOGDescriptor::getDefaultPeopleDetector());
std::vector<cv::Rect> found;
// 画像,検出結果,閾値(SVMのhyper-planeとの距離),
// 探索窓の移動距離(Block移動距離の倍数),
// 画像外にはみ出た対象を探すためのpadding,
// 探索窓のスケール変化係数,グルーピング係数
hog.detectMultiScale(img, found, 0.2, cv::Size(8,8), cv::Size(16,16), 1.05, 2);
std::vector<cv::Rect>::const_iterator it = found.begin();
std::cout << "found:" << found.size() << std::endl;
for(; it!=found.end(); ++it) {
cv::Rect r = *it;
// 描画に際して,検出矩形を若干小さくする
r.x += cvRound(r.width*0.1);
r.width = cvRound(r.width*0.8);
r.y += cvRound(r.height*0.07);
r.height = cvRound(r.height*0.8);
cv::rectangle(img, r.tl(), r.br(), cv::Scalar(0,255,0), 3);
}
// 結果の描画
cv::namedWindow("result", CV_WINDOW_AUTOSIZE|CV_WINDOW_FREERATIO);
cv::imshow( "result", img );
cv::waitKey(0);
}
it is made for a non iOS enviroment, however you can simply replace all highgui calls for
native iOS stuff.
You can get a very good image handling for opencv library from here:
http://aptogo.co.uk/2011/09/opencv-framework-for-ios/
so what you should really care about in that code is just this part:
cv::HOGDescriptor hog;
hog.setSVMDetector(cv::HOGDescriptor::getDefaultPeopleDetector());
std::vector<cv::Rect> found;
// 画像,検出結果,閾値(SVMのhyper-planeとの距離),
// 探索窓の移動距離(Block移動距離の倍数),
// 画像外にはみ出た対象を探すためのpadding,
// 探索窓のスケール変化係数,グルーピング係数
hog.detectMultiScale(img, found, 0.2, cv::Size(8,8), cv::Size(16,16), 1.05, 2);
std::vector<cv::Rect>::const_iterator it = found.begin();
std::cout << "found:" << found.size() << std::endl;
for(; it!=found.end(); ++it) {
cv::Rect r = *it;
// 描画に際して,検出矩形を若干小さくする
r.x += cvRound(r.width*0.1);
r.width = cvRound(r.width*0.8);
r.y += cvRound(r.height*0.07);
r.height = cvRound(r.height*0.8);
cv::rectangle(img, r.tl(), r.br(), cv::Scalar(0,255,0), 3);
}
For a BRIEF:
// You get your img into a cv mat from the uiimage or whatever.
cv::Mat gray_img;
cv::cvtColor(img, gray_img, CV_BGR2GRAY);
cv::normalize(gray_img, gray_img, 0, 255, cv::NORM_MINMAX);
std::vector<cv::KeyPoint> keypoints;
std::vector<cv::KeyPoint>::iterator itk;
cv::Mat descriptors;
//
// threshold=0.05, edgeThreshold=10.0
cv::SiftFeatureDetector detector(0.05,10.0);
detector.detect(gray_img, keypoints);
// Brief に基づくディスクリプタ抽出器
cv::BriefDescriptorExtractor extractor;
cv::Scalar color(50,50,155);
extractor.compute(gray_img, keypoints, descriptors);
// 32次元の特徴量 x keypoint数
for(int i=0; i<descriptors.rows; ++i) {
cv::Mat d(descriptors, cv::Rect(0,i,descriptors.cols,1));
std::cout << i << ": " << d << std::endl;
}
And you have your result.

Draw background image in gtk - none of my attempts work

I've been trying to set a background image on a gtk widget without success, even after trying 4 different approaches.
The following program contains 3 approaches (the 4th approach involves no code). I compiled it using MinGW (g++ 4.5.0) and gtkmm 2.4. The APPROACH macro can be set to 1, 2 or 3 in order to choose which approach to compile. I've also added references in the comments, so you can find out where I got the ideas from.
#include <iostream>
#include <gtkmm/main.h>
#include <gtkmm/alignment.h>
#include <gtkmm/box.h>
#include <gtkmm/entry.h>
#include <gtkmm/eventbox.h>
#include <gtkmm/frame.h>
#include <gtkmm/image.h>
#include <gtkmm/label.h>
#include <gtkmm/table.h>
#include <gtkmm/window.h>
// Set this to 1, 2 or 3 to try different ways of drawing the background
// Set to 0 to load no background at all
#define APPROACH (0)
// Making this alignment global in order to modify it from drawBackground
Gtk::Alignment* alignment;
bool drawBackground(GdkEventExpose* event) {
std::cout << "Draw background" << std::endl;
// Load background image
Glib::RefPtr<Gdk::Pixbuf> pixbuf = Gdk::Pixbuf::create_from_file("background.jpg");
Glib::RefPtr<Gdk::Pixmap> pixmap;
Glib::RefPtr<Gdk::Bitmap> mask;
pixbuf->render_pixmap_and_mask(pixmap, mask,0);
{
// Test that pixbuf was created correctly
Glib::RefPtr<Gdk::Pixbuf> back_to_pixbuf = Gdk::Pixbuf::create((Glib::RefPtr<Gdk::Drawable>)pixmap, 0, 0, pixbuf->get_width(), pixbuf->get_height());
back_to_pixbuf->save("back_to_pixbuf.png", "png");
}
#if APPROACH == 1
// Approach 1: draw_pixbuf
// Ref: http://islascruz.org/html/index.php/blog/show/Image-as-background-in-a-Gtk-Application..html
Glib::RefPtr<Gtk::Style> style = alignment->get_style();
alignment->get_window()->draw_pixbuf(style->get_bg_gc(Gtk::STATE_NORMAL), pixbuf, 0, 0, 0, 200, pixbuf->get_width(), pixbuf->get_height(), Gdk::RGB_DITHER_NONE, 0, 0);
#endif
#if APPROACH == 2
// Approach 2: set_back_pixmap
// Ref: http://www.gtkforums.com/viewtopic.php?t=446
// http://stackoverflow.com/questions/3150706/gtk-drawing-set-background-image
alignment->get_window()->set_back_pixmap(pixmap);
#endif
}
int main (int argc, char *argv[])
{
Gtk::Main kit(argc, argv);
Gtk::Window w;
Gtk::VBox mainBox;
// Top image
Gtk::Image topImage("header.jpg");
mainBox.pack_start(topImage,false,false,0);
// Middle alignment
alignment = Gtk::manage(new Gtk::Alignment);
mainBox.pack_start(*alignment,true,true,0);
// Create widget
Gtk::Alignment mywidget(0.5, 0.5, 0.1, 0.9);
Gtk::Table table;
Gtk::Label label1("Username"); table.attach(label1,0,1,0,1);
Gtk::Label label2("Password"); table.attach(label2,0,1,1,2);
Gtk::Entry entry1; table.attach(entry1,1,2,0,1);
Gtk::Entry entry2; table.attach(entry2,1,2,1,2);
Gtk::Button button("Login"); table.attach(button,1,2,2,3);
mywidget.add(table);
// Put widget in middle alignment
alignment->add(mywidget);
// Try to change the background
#if APPROACH == 1 || APPROACH == 2
alignment->signal_expose_event().connect(sigc::ptr_fun(&drawBackground), true);
#endif
#if APPROACH == 3
// Approach 3: modify the style using code
// Ref: http://www.gtkforums.com/viewtopic.php?t=446
// Load background image
Glib::RefPtr<Gdk::Pixbuf> pixbuf = Gdk::Pixbuf::create_from_file("background.jpg");
Glib::RefPtr<Gdk::Pixmap> pixmap;
Glib::RefPtr<Gdk::Bitmap> mask;
pixbuf->render_pixmap_and_mask(pixmap, mask,0);
Glib::RefPtr<Gtk::Style> style = alignment->get_style()->copy();
style->set_bg_pixmap(Gtk::STATE_NORMAL,pixmap);
style->set_bg_pixmap(Gtk::STATE_ACTIVE,pixmap);
style->set_bg_pixmap(Gtk::STATE_PRELIGHT,pixmap);
style->set_bg_pixmap(Gtk::STATE_SELECTED,pixmap);
style->set_bg_pixmap(Gtk::STATE_INSENSITIVE,pixmap);
alignment->set_style(style);
#endif
// Approach 4: modify share\themes\MS-Windows\gtk-2.0
// adding the following line
// bg_pixmap[NORMAL] = "D:\\path\\to\\file\\background.jpg"
// in the style "msw-default" section
// Ref: http://lists.ximian.com/pipermail/gtk-sharp-list/2005-August/006324.html
// Show the window
w.add(mainBox);
w.show_all();
kit.run(w);
return 0;
}
Links to images I used: header.jpg background.jpg
The layout mimics that of my actual program. The main window contains a Gtk::VBox with a header image on top and an Gtk::Alignment at the bottom. The contents of this alignment will change over time but I want it to have a background image always visible.
When loading no background at all, the header image loads correctly and the window looks like this:
Approach 1 is the one that is closer to work, though it hides the labels and the buttons:
Approaches 2 and 3 look the same as loading no background. Besides, approach 2 gives me the following error message:
(test-img-fondo.exe:1752): Gdk-CRITICAL **: gdk_window_set_back_pixmap: assertion `pixmap == NULL || !parent_relative' failed
Finally, in approach 4, I attempt to modify share\themes\MS-Windows\gtk-2.0 by adding the following line
bg_pixmap[NORMAL] = "D:\\path\\to\\file\\background.jpg"
in the style "msw-default" section. It doesn't work either.
So, has anyone succesfully drawn a background image on a Gtk widget? Is this possible at all? Any changes in my code that would make this work? Any workarounds?
All help is greatly appreciated.
I think I've solved it myself. Use approach 1 but change this line
alignment->signal_expose_event().connect(sigc::ptr_fun(&drawBackground), true);
for this:
alignment->signal_expose_event().connect(sigc::ptr_fun(&drawBackground), false);
This way, the call to drawBackground occurs before gtk calls its own handlers.
I should also point out that, in a real program, the images should be loaded once outside of drawBackground.