Method FindWindowPlacementAndResize

src/window.cpp:1476–1528

* Resize window towards the default size. * Prior to construction, a position for the new window (for its default size) * has been found with LocalGetWindowPlacement(). Initially, the window is * constructed with minimal size. Resizing the window to its default size is * done here. * @param def_width default width in pixels of the window * @param def_height default height in pixels of the wi

 * @see Window::Window(), Window::InitializeData(), Window::InitializePositionSize()
 */
void Window::FindWindowPlacementAndResize(int def_width, int def_height, bool allow_resize)
{
	if (allow_resize) {
		def_width  = std::max(def_width,  this->width); // Don't allow default size to be smaller than smallest size
		def_height = std::max(def_height, this->height);
		/* Try to make windows smaller when our window is too small.
		 * w->(width|height) is normally the same as min_(width|height),
		 * but this way the GUIs can be made a little more dynamic;
		 * one can use the same spec for multiple windows and those
		 * can then determine the real minimum size of the window. */
		if (this->width != def_width || this->height != def_height) {
			/* Think about the overlapping toolbars when determining the minimum window size */
			int free_height = _screen.height;
			const Window *wt = FindWindowById(WC_STATUS_BAR, 0);
			if (wt != nullptr) free_height -= wt->height;
			wt = FindWindowById(WC_MAIN_TOOLBAR, 0);
			if (wt != nullptr) free_height -= wt->height;

			int enlarge_x = std::max(std::min(def_width  - this->width,  _screen.width - this->width),  0);
			int enlarge_y = std::max(std::min(def_height - this->height, free_height   - this->height), 0);

			/* X and Y has to go by step.. calculate it.
			 * The cast to int is necessary else x/y are implicitly cast to
			 * unsigned int, which won't work. */
			if (this->resize.step_width  > 1) enlarge_x -= enlarge_x % (int)this->resize.step_width;
			if (this->resize.step_height > 1) enlarge_y -= enlarge_y % (int)this->resize.step_height;

			ResizeWindow(this, enlarge_x, enlarge_y, true, false);
			/* ResizeWindow() calls this->OnResize(). */
		} else {
			/* Always call OnResize; that way the scrollbars and matrices get initialized. */
			this->OnResize();
		}
	}

	int nx = this->left;
	int ny = this->top;

	if (nx + this->width > _screen.width) nx -= (nx + this->width - _screen.width);

	const Window *wt = FindWindowById(WC_MAIN_TOOLBAR, 0);
	ny = std::max(ny, (wt == nullptr || this == wt || this->top == 0) ? 0 : wt->height);
	nx = std::max(nx, 0);

	if (this->viewport != nullptr) {
		this->viewport->left += nx - this->left;
		this->viewport->top  += ny - this->top;
	}
	this->left = nx;
	this->top = ny;

	this->SetDirty();
}

/**
 * Decide whether a given rectangle is a good place to open a completely visible new window.