The Back button in the top left corner of my touch user interface is a little hard to press on a resistive touchscreen, because the touch events are not so precise at the borders of the screen.
The visual size of the button can't really be increased because the screen space is needed for other things. Thus I would like to increase only the clickable area of the button. So when the user touches somewhere in the top left corner of the screen (as marked in red), the back button should be pressed. Note that the red area also overlaps another button. Ideally, the visual button state would also change to the "pressed" state.
Can anyone give me some pointers in the right direction? I have considered the following things, but I'm unsure which would work.
Overlaying the actual button with a larger, invisible button, painted with a transparent brush. But I have no idea how I could paint the smaller button as "pressed" when the user is pressing the invisible button.
Creating a new class based on QWidget, which has the size of the red area (with invisible background) and contains the actual button. Then relay touch events to the button so that it is pressed when the user touches the empty area.
Subclassing QPushButton and reimplementing QAbstractButton::hitButton to accept points outside of the button's area. But I guess that function would probably isn't even called when I touch outside the widget area.
To occupy more vertical space inside a layout, set buttons vertical policy to expanding.
To increase the clickable area without increasing the visual size, increase the margin.
To have the back button overlapping other buttons, don't put it to a layout. Instead set its parent directly and move it to the corner.
backButton = new QPushButton("< Back", mainWindow);
backButton->setStyleSheet("margin: 30;");
backButton->show();
backButton->resize(150, 90);
backButton->move(-30, -30);
Related
I've got a QToolbar with QToolButtons. The buttons receive focus with a manual ->setFocus(). However I need the focus marking area (blue) to be expanded to the size of the full area as while hovered.
Is there a way to do that?
Hover + focus
Focus (1st button), hover (2nd button)
I have a problem with an icon I'm overlapping over other image
Originally, the image I'm showing has a hover popover that displays information about that product, we're aggregating a new feature to mark the products for example as removed or forbidden, the problem is that when the image icon overlaps the product's then it takes the mouse over event causing that when the mouse is over it the popover doesn't display.
Adding a listener to the icon to trigger the popover would be problematic (a bit difficult and disrupts the continuity of the popover being displayed)
Is there css trick or other way in which the icon can be inhibited from taking events and letting the underlying image to throw the events, kind of making the icon "transparent" for events? (don't know if this is possible at all)
Thanks in advance!
Sample overlapped images
When I resize a window, I can do so using the top,bottom,left or right sides or top-right,top-left,bottom-right or bottom-left corners.
Is there a way to know which one is used when I'm resizing?
I don't know if there is an elegant solution because different operating systems handle borders differently.
My suggestion is
to compute the difference between the current and previous window size each time it is drawn
Get the mouse cursor's position.
If the window X changes, the border used is probably the left or right -- whichever the mouse cursor is closest to. If the Y changes, probably the top or bottom border the cursor is closest to.
If both change, the corner the mouse cursor is closest to is probably it.
A few corner cases may come up. For example, a window can be resized on some systems using the keyboard. It can potentially also be resized programatically, like when the user changes to a resolution too low to contain your window. These things can be handled in most cases by detecting of the mouse button is clicked while the resize is taking place.
Also, it is possible to resize just the width or height from the corner. In these cases, you may have to choose a threshold for mouse distance from corner that would decide whether it is actually at a corner.
I have an image that I show inside a canvas which I can zoom in on.
The problem is that when zoomed in, I try to drag the image, I can see the outline of the image in the foreground, (i.e.) outside the canvas boundary.
Is there anyway to tell the dragHandler to crop the "grabbed" image outside the canvas boundary?
In my experience using the built in drag/drop flex stuff is overkill for something that involves moving a component around in a canvas.
The easier way to do this (in my opinion) would be to listen for mouse down/up/move the image around in the canvas yourself.
When you detect a mouse down on your image, add a listener for mouse move (pro tip: make sure you set useCapture to true when calling addEventListener) and store the position of the mouse relative the origin of your image. Then whenever you get a mouse move, change the position of your image within your canvas taking into account the position of the mouse within the image (which you stored on mouse down). Keep doing this until mouse up occurs, then remove your mouse move listener.
There are some additional finer points to account for (what if the user drags outside of the canvas? Or outside of the browser window?), but this will get you started.
Hope that helps.
I'm doing an application in flex where I draw different sprites inside a canvas. Depending of the dimensions, scrollbars can be appear. I would like to move the "image" with the movement of the mouse as you can see at the Adobe Reader when you are reading a document with zoom (hand mouse icon). In this way, you dont have to touch the scrollbar.
I'm start trying with drag and drop properties of the canvas, setting the position of the scrollbar according with the movement of the mouse but that is not as I expect.
Any ideas or suggestions?
Thanks in advance.
Recipe:
Listen for the mouseMove (MouseEvent.MOUSE_MOVE) event on the canvas
In event listener, examine event.localX, event.localY
Based on those values and the canvas's width and height, set the canvas's horizontalScrollPosition and verticalScrollPosition accordingly
Hope this helps.
What you can do is, change the position of the scrollbar , when the mouse reaches the last 20 pixels on the left or the right, or the top and bottom.
What you would really need to do is, have a mouseMove listener on the whole application, and when the mouse is within the end ranges of any of the sides, you can use the scroll.scrollTo function to move the scrollbars.