Add scale for image

Gtk4_Reset/src/apps/ImageApp.hh

@@ -1,41 +0,0 @@
-#pragma once
-
-#include <gtkmm.h>
-#include "MyImage.hh"
-
-class ImageApp : public Gtk::ApplicationWindow
-{
-public:
-    ImageApp();
-    
-private:
-    // Child widgets
-    Gtk::ScrolledWindow sw;
-    MyImage image_area;
-    Gtk::Box main_box, btnbox;
-    Gtk::Button btnopen;
-    Gtk::Scale scale;
-    Gtk::Overlay overlay;
-    Glib::RefPtr<Gtk::Adjustment> m_adjustment, hadjustment, vadjustment;
-    Glib::RefPtr<Gtk::FileChooserNative> dialog;
-
-    // Gesture control
-    Glib::RefPtr<Gtk::GestureDrag> gesture_drag;
-    Glib::RefPtr<Gtk::GestureMultiPress> gesture_click;
-    void drag_begin(double x, double y);
-    void drag_update(double x, double y);
-    void drag_end(double x, double y);
-    void move_to(double x, double y);
-
-    // Menu for image control
-    Gtk::PopoverMenu popover;
-    void press(int n_press, double x, double y);
-
-    // Signal Handlers
-    void btnopen_clicked();
-    void dialog_response(int response_id);
-    void scale_changed();
-    void image_zoom_in();
-    void image_zoom_out();
-    void image_zoom_reset();
-};

Gtk4_Reset/src/image_app/ImageApp.cpp

@@ -19,6 +19,14 @@ struct _ImageApp
 
 G_DEFINE_TYPE(ImageApp, image_app, GTK_TYPE_APPLICATION_WINDOW)
 
+static gboolean image_app_change_scale(GtkRange *range, GtkScrollType *scroll,
+                                   double scale_value, ImageApp *app)
+{
+    my_image_scale_draw(app->image_view, scale_value);
+    gtk_range_set_value(range, scale_value);
+    return TRUE;
+}
+
 static void image_app_dialog_response(GObject *dialog, GAsyncResult *result, gpointer data)
 {
     GFile *file;
@@ -57,6 +65,7 @@ static void image_app_init(ImageApp *self)
     self->image_scale = gtk_scale_new_with_range(GTK_ORIENTATION_HORIZONTAL, 0.1, 10.0, 0.1);
     self->btnopen = gtk_button_new_with_label("Open Image");
     g_signal_connect(self->btnopen, "clicked", G_CALLBACK(btnopen_clicked), self);
+    g_signal_connect(self->image_scale, "change-value", G_CALLBACK(image_app_change_scale), self);
 
     // Initalize widgets
     gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(self->image_sw),

Gtk4_Reset/src/image_app/MyImage.cc

@@ -1,79 +0,0 @@
-#include "MyImage.hh"
-
-MyImage::MyImage()
-    : scale_radio(1.0)
-{
-}
-
-MyImage::~MyImage()
-{
-}
-
-bool MyImage::on_draw(const Cairo::RefPtr<Cairo::Context> &cr)
-{
-    if (!image)
-    {
-        return false;
-    }
-
-    // Set the default size for drawing area
-    set_size_request(surface->get_width() * scale_radio,
-                     surface->get_height() * scale_radio);
-
-    cr->scale(scale_radio, scale_radio);
-    cr->set_source(surface, 0, 0);
-
-    cr->paint();
-
-    return true;
-}
-
-void MyImage::scale_draw(double scale)
-{
-    // Set the scale radio and scale
-    if (scale <= 0)
-    {
-        scale_radio = 0.1;
-        return;
-    }
-    if (scale > 10.0)
-    {
-        scale_radio = 10.0;
-        return;
-    }
-    scale_radio = scale;
-    queue_draw();
-}
-
-void MyImage::set_pixbuf(const Glib::RefPtr<Gdk::Pixbuf> &pixbuf)
-{
-    if (image)
-    {
-        image.reset();
-    }
-
-    image = pixbuf;
-
-    if (!surface)
-    {
-        // Create a surface
-        surface = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32,
-                                              image->get_width(), image->get_height());
-    }
-    else
-    {
-    }
-
-    // Get Image Size
-    int width = image->get_width();
-    int height = image->get_height();
-    // Draw the image in the middle of the surface, or (if the image is
-    // larger than the drawing area) draw the middle part of the image.
-    auto cr = Cairo::Context::create(surface);
-    Gdk::Cairo::set_source_pixbuf(cr, image,
-                                  (width - image->get_width()) / 2, (height - image->get_height()) / 2);
-    cr->paint();
-
-    // ReDraw the draw area
-    queue_draw();
-}

Gtk4_Reset/src/image_app/MyImage.cpp

@@ -25,6 +25,7 @@ static void my_image_draw(GtkDrawingArea *area, cairo_t *cr,
 
     // Scale the image and draw
     cairo_set_source_surface(cr, image_view->surface, 0, 0);
+    
     cairo_surface_set_device_scale(image_view->surface,
                                    image_view->scale_radio, image_view->scale_radio);
     cairo_paint(cr);
@@ -81,14 +82,14 @@ void my_image_scale_draw(MyImage *image, double scale)
     // Set the scale radio and scale
     if (scale <= 0)
     {
-        image->scale_radio = 0.1;
+        image->scale_radio = 10.0;
         return;
     }
     if (scale > 10.0)
     {
-        image->scale_radio = 10.0;
+        image->scale_radio = 0.1;
         return;
     }
-    image->scale_radio = scale;
+    image->scale_radio = 1.0 / scale;
     gtk_widget_queue_draw(GTK_WIDGET(image));
 }

Gtk4_Reset/src/image_app/MyImage.hh

@@ -1,22 +0,0 @@
-#pragma once
-
-#include <gtkmm.h>
-
-class MyImage : public Gtk::DrawingArea
-{
-public:
-    MyImage();
-    virtual ~MyImage();
-    // Set a Pixbuf to draw
-    void set_pixbuf(const Glib::RefPtr<Gdk::Pixbuf> &pixbuf);
-    // Scale the image
-    void scale_draw(double scale);
-
-protected:
-    bool on_draw(const Cairo::RefPtr<Cairo::Context> &cr) override;
-
-private:
-    double scale_radio;
-    Cairo::RefPtr<Cairo::ImageSurface> surface;
-    Glib::RefPtr<Gdk::Pixbuf> image;
-};